LX Series Fan Coil Unit (FCU) Controller User’s Guide

LX Series Fan Coil Unit (FCU) ControllerUser’s Guide

Code No. LIT-12011487Issued June 22, 2009

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Sensor Configuration Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Control Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

LONMARK Functional Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Units in LONWORKS Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Language Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Selecting a Measurement System or Selecting a Language . . . . . . . . . . . . . . . . . . . . . 14

Installing and Launching the Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Fan Coil Unit Controller Installation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

10k Ohm or Digital Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4 to 20 mA Analog Input, Externally Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Sensors and Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Bypass Contact Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Discharge Temperature Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Fan Speed Selector Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Fan State Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Mode Selector Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Occupancy Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Setpoint Offset Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Space Temperature Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Water Temperature Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Window Contact Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

1LX Series Fan Coil Unit (FCU) Controller User’s Guide

Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Analog Output Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Digital Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Staged Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Output Selections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Network Variables Used for Mode Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Occupied Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Starting Occupied Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Ending Occupied Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Unoccupied Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Starting Unoccupied Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Ending Unoccupied Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Bypass Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Starting Bypass Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Ending Bypass Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Standby Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Starting Standby Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Ending Standby Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Slave Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

State Selection and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Supervisory Control and Scheduling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Calculating the Space Temperature Setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

The Effect of nviSetPoint on the Active Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

The Effect of a Setpoint Offset on the Active Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Cooling State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Mechanical Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Cooling Demand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Cooling Output Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Ending the Cooling State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

LX Series Fan Coil Unit (FCU) Controller User’s Guide2

Heating States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Heating Demand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Heating Output Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Cooling Outputs Used to Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Ending the Heating State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Fan Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Terminal Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Heating Terminal Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Cooling Terminal Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Networking Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Slave Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Load Shedding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Setting up Network Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Network Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Optimum Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Requirements for Optimum Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

The PID Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Proportional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Integral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

How It Is Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Derivative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Deadband . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Alarm Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Alarm Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Alarm Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Alarm Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

LX Series Fan Coil Unit (FCU) Controller User’s Guide 3

Heartbeat Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Disconnect Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

User-Set Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Setting up the Fan Coil Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Persistent Network Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Setting Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Input Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Configuring an Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Heartbeat (Max Send Time). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Throttle (Min Send Time). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Delta Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Override Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Default Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Sensor Hardware Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Input Signal Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Signal Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Thermistor Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Offset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Max Value, Min Value. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Reverse. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Increment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

TransTable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Get Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Configuring an Input Represented as a LONMARK Object . . . . . . . . . . . . . . . . . . . . . . . 60

Output Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Output Signal Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Configuring an Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Configuring an Output Represented as a LONMARK Object. . . . . . . . . . . . . . . . . . . . . . . . . 64

Heating-Cooling Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Optimum Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65


Fan-Valve Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

PID Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Alarm Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Space Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Discharge Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Fan Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Network Input Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Heartbeat Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Network Output Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Object Manage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Object Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Communication Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Electrical Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Out of Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

In Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

In Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Out of Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Network Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

nviApplicMode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

nviDischargeTemp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

nviEnergyHoldOff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

nviExtCmdOutputx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

nviFanSpeedCmd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

nviHotWater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

nviOccCmd and nviOccManCmd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

nviOutdoorTemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

nviSetPoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

nviSetPtOffset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

nviShedding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

LX Series Fan Coil Unit (FCU) Controller User’s Guide 5

nviSlave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

nviSpaceTemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

nviWaterTemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

nvoCoolOutput. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

nvoCtrlOutputx. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

nvoEffectSetPt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

nvoFanSpeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

nvoFCalarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

nvoFCstate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

nvoHeatOutput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

nvoHwInputx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

nvoOccState . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

nvoSpaceTemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

nvoTerminalLoad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

nvoUnitStatus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

nvoWaterTemp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Standard Network Variable Types (SNVTs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Change Network Variable Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

SNVT_hvac_mode (108) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

SNVT_hvac_status (112) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Alarm State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

SNVT_lev_percent (81) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

SNVT_occupancy (109) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

SNVT_switch (95). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Switch Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

SNVT_temp_p (105) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

SNVT_tod_event (128) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90


LX Series Fan Coil Unit (FCU) ControllerUser's Guide

IntroductionThe LX Series FCU Controller seamlessly integrates into a LONWORKS® network for the control of almost any fan coil unit due to its wide range of output types and LONMARK® certification.

The LX Series FCU Controller controls the following equipment:

• up to three fan speeds

• three stages of mechanical heating or cooling

• modulating heating or cooling valves

• reversing valves for applications requiring a heat pump

• floating valves for heating or cooling

• variable speed fans

The FCU Controller has five Digital Outputs (DOs) supplying 1.0 A at 24 VAC. These outputs produce digital or Pulse Width Modulation (PWM) signals.

Two tri-mode Analog Outputs (AOs) are also on the circuit board. These outputs provide the following signals:

• linear signals over a 0–10 VDC range

• 10 VDC digital or PWM signals

• digital signals of 60 mA at 12 VDC

The controller has six inputs, each capable of one of 10 possible input types. Inputs have 12-bit resolution and are configured completely by software.

For easy maintenance and installation, the controller is equipped with plug-in connectors that accept flat cable or wires. The controller uses a TP/FT-10 78 kbps network configuration.

The information in this guide helps you to set up the FCU, understand the operation of the FCU, and troubleshoot problems. Information is organized to follow the FCU configuration wizard menu.

Sensor Configuration WizardThe Fan Coil Unit Controller incorporates the Johnson Controls® sensor configuration wizard. The wizard provides powerful and simple configuration tools for the hardware inputs. You can only select digital or analog inputs through the software. You do not need to move any circuit board jumpers.

LX Series Fan Coil Unit (FCU) Controller User's Guide 7

Analog Input (AI) signal types (resistive, voltage, and current) are selected in software without hardware jumpers. Built-in conversion tables are provided for a large number of thermistors or other sensor types. You can easily create custom conversion tables by setting the offset, minimum, and maximum values in one dialog box for the input.

The sensor configuration wizard also provides direct access to network properties of the analog or digital input including the Standard Network Variable Type (SNVT), Heartbeat, Send on Delta, Override, Default Value, and Throttle settings. All of the input features are in one place; therefore, it is not necessary to switch back and forth between dialog boxes to fully configure an input.

The sensor configuration wizard provides warnings of configuration errors as they occur, allowing you to correct mistakes quickly.

The sensor configuration wizard is a separate wizard shown in the LX-FCUL Wizard view of the device (see Figure 8). Each hardware input is represented by a separate LONMARK object. To configure each input, select the hardware input on the left side of the view, and the Sensor Configuration wizard on the right side of the view. Click Launch to open the sensor configuration wizard. With the wizard, you can control network inputs not directly controlled by the FCU Controller.

Control FeaturesThe Fan Coil Unit Controller provides Proportional plus Integral plus Derivative (PID) loops for advanced control of discharge temperature and space temperature. Each PID loop has an individual, configurable deadband. In addition, each PID loop provides gain and time adjustment for the integral and derivative terms, and gain adjustment for the proportional term.

A PI Loop controls only space temperature. However, the presence of the derivative term adds the ability to precisely adjust space temperature control to provide better comfort and increased savings.

Often associated with air handlers, the FCU also provides the advanced control features of Optimum Start and load shedding.

The Optimum Start function maintains statistics that enable the Fan Coil Unit Controller to predict the warm-up or cooldown time period needed to make the building ready for occupancy. The precise Optimum Start period is calculated every day using the current outdoor air temperature.

LX Series Fan Coil Unit (FCU) Controller User's Guide8

LONMARK Functional ProfileThe LX Series Fan Coil Unit Controller uses LONWORKS network protocol and is LONMARK network certified for interoperability on any LONWORKS network. The FCU is set up through its own configuration wizard and through the sensor and actuator configuration wizards. Use FX Workbench to install the device onto the network and bind the network variable connections.

Figure 1 illustrates that the Fan Coil Unit Controller meets the LONMARK standard by providing the Network Variable Inputs (NVIs), Network Variable Outputs (NVOs), and Configuration Properties (CPs) specified by the profile. In addition, the Fan Coil Unit Controller provides many extra network variable inputs and outputs. These extra network variables provide a greater flexibility and a greater number of functions than required in the LONMARK profile. For example, you can use network input nviSlave to slave the FCU to another unit. Network output nvoUnitStatus enables the FCU to act as the master node.


Fan Coil

Object Type #8020

Configuration Properties

Occ. Temperature Set Points (mandatory)Maximum Send Time (mandatory)

Minimum Send Time (optional)

nviSpaceTempSNVT_temp_p

MandatoryNetworkVariables

ManufacturerNetworkVariables

nvoTerminalLoadSNVT_lev_percent

nvoCtrlOutput1SNVT_switch

nvoCtrlOutput7SNVT_switch

Manufacturer Configuration PropertiesSee section “Viewing and Directly Editing Input

Configuration Properties” for details

nvoUnitStatusSNVT_hvac_status

nviSetPointSNVT_temp_p

nvoFCstate

nviApplicModeSNVT_hvac_mode

nviSetPtOffsetSNVT_temp_p

nviOccManCmdSNVT_occupancy

nviEnergyHoldOffSNVT_switch

nviSlaveSNVT_lev_percent

nviSheddingSNVT_switch

nviHotWaterSNVT_switch

nvoHeatOutputSNVT_lev_percent

nvoCoolOutputSNVT_lev_percent

nvoFanSpeedSNVT_switch

nvoDischAirTempSNVT_temp_p

nvoEffectSetPtSNVT_temp_p

nvoSetPtOffsetSNVT_temp_p

nvoHwInput1SNVT_temp

nvoHwInput6SNVT_temp

SNVT_state_64

nviFanSpeedCmdSNVT_switch

nviOccCmdSNVT_tod_event

nviWaterTempSNVT_temp_p

nviDischAirTempSNVT_temp_p

nviDischAirTempSNVT_temp_p

nviOutdoorTempSNVT_temp_p

OptionalNetworkVariables

nvoSpaceTempSNVT_temp_p

nvoOccStateSNVT_occupancy

nviExtCmdOutput1SNVT_switch

SNVT_state_64nvoFCalarm

nvoFileDirectorySNVT_address

nvoStatusSNVT_obj_status

...

...

nviExtCmdOutput7SNVT_switch

...nvoWaterTempSNVT_temp_p

Figure 1: LX Series Fan Coil Unit Controller:LONMARK Functional Profile


Figure 2 shows the Fan Coil Unit Controller input object and the output object.

The input object has conversion tables and hardware properties present as configuration properties in the area marked Manufacturer Configuration Properties. By choosing from a list of standard thermistors, you can select different conversion properties. The conversion tables configuration property allows you to create your own custom tables. Hardware properties, located in the same area, allow you to modify your input from the software object.

LX-FCUL-1 Hardware InputObject Type #1

nvoHwInputxSNVT_xxx


Offset (optional)Maximum Range (optional)Minimum Range (optional)

Minimum Send Delta (optional)Maximum Send Time (optional)Minimum Send Time (optional)

Override Value (optional)


Manufacturer Configuration Properties

Object Major VersionObject Minor Version

Input Signal ConditioningHardware PropertiesTranslation Table

Default Value

LX-FCUL-1 Hardware OutputObject Type #3

nviExtCmdOutputxSNVT_switch


Maximum Receive Time (optional)Override Value (optional)

MandatoryNetwork

Variables


Object Major VersionObject Minor Version

Output Signal ConditioningPWM Period

Translation TableDefault Value

Figure 2: LX Series Fan Coil Unit ControllerInputs and Outputs


The node object displays the nvoFCstate and nvoFCalarm variables as manufacturer’s variables. These variables provide information about the alarm conditions and the operating state of the device.

Units in LONWORKS NetworksNote: Use this section if you are using the Imperial System of measure.

The Imperial System and the International System (SI) are the two main measurement systems used today. Table 1 compares Imperial units and SI units.

Echelon® SNVTs are based upon SI units. Therefore, the most basic structure of the LONWORKS network is SI based. This basis can lead to some unavoidable problems in data conversion if you are using Imperial units.

Table 1: Comparing Imperial and SI UnitsImperial Units SIinch centimeter

yard meter

mile kilometer

degrees Fahrenheit degrees Centigrade

LX-FCUL-1 NodeObject Type #0

nvoStatusSNVT_obj_status


Location (optional)Device Major Version (optional)Device Minor Version (optional)

nviRequestSNVT_obj_request


OptionalNetworkVariables

ManufacturerNetworkVariables

nvoFileDirectorySNVT_address

nvoFCstateSNVT_state_64

nvoFCalarmSNVT_state_64


Maximum Send Time

Figure 3: LX Series Fan Coil Unit ControllerNode Object Type


FX Workbench and other utilities provide some automatic conversion between SI and Imperial units. However, these are not ideal conversions because a whole number in one system becomes a long decimal fraction in the other. For example, 72°F is approximately equal to 22.2222°C.

The values created by converting Imperial to SI, or SI to Imperial, are subject to rounding errors. If you enter an Imperial value into a LONWORKS SNVT by using the FCU configuration wizard, the value is converted after it is entered, then rounded and written to the SNVT. When you want to monitor the SNVT, the value must be read from the SNVT, converted, and rounded again before it is displayed. Due to the two conversions and two rounding operations, the value may differ slightly from what you originally entered (Figure 4).

The same process and resulting rounding error applies to Standard Configuration Property Types (SCPTs).

Instructions for changing or modifying the units of measure used on your computer are provided in the Selecting a Measurement System or Selecting a Language section.

Language SelectionThe following may require you to change your language settings:

• You changed your regional settings by selecting a different region in the Regional and Language Options dialog box.

• You are working on a site that is in a linguistic region other than your own.

• You are dissatisfied with the language displayed on program menus and dialog boxes.

Figure 4: Writing and Reading Data in Imperial Units in the LONWORKS Network

Value is written in Imperial Units.

Value is translated to SI units.

Value is rounded.

Value is read from SNVT.

Value is translated to SI units.

Value is rounded.

Data is displayed for monitoring in Imperial Units.

Units

Value is stored in SNVT.


You can change your language settings in the Advanced tab of the Regional and Language Options dialog box. Instructions are provided in the following Selecting a Measurement System or Selecting a Language section.

Selecting a Measurement System or Selecting a LanguageTo select units of measurement or to select a language:

1. In Microsoft® Windows XP® operating system, click Start > Control Panel. The Control Panel appears.

2. In the Control Panel, open Date, Time, Language, and Regional Options.

3. Under the list titled Pick a Task, select and open the second item titled Change the format of numbers, dates, and times (Figure 5).

Figure 5: Date, Time, Language, and Regional Options Screen


4. Select your language region from the drop-down list provided. The number, time, and date formats fill automatically (Figure 6).

5. In the Number box, verify the number format uses a decimal point to indicate numerals representing values less than 1. For example, use 123,456,789.00, not 123 456 789,00. You must use a decimal point for the correct display of numerals.

6. In the Regional Options dialog box, click Customize.

Figure 6: Regional and Language Options Dialog Box


7. Click the drop-down arrow next to the box labeled Measurement system and select Metric (Figure 7).

8. Verify the Decimal symbol box contains a decimal point. If the Decimal symbol box does not contain a decimal point, select the symbol in the box and click Apply.

9. Click OK.

10. Click the Advanced tab and choose a language region by selecting from the drop-down list. Verify the correct language appears on program menus.

11. Click OK.

You have now set the units to appear in the wizard.

Note: If you have chosen to display Imperial units, remember that the SNVTs are still using SI units. If you are viewing the data in Imperial units, you are viewing a converted, rounded value.

Figure 7: Customize Regional Options Dialog Box


Installing and Launching the WizardTo install the wizard:

1. From your FX Workbench installation CD, locate the LX-FCUL Configuration Setup.exe file.

2. Double-click the .exe file.

3. Follow the on-screen prompts for installation.

To launch the wizard:

1. In the Lon Device Manager view of FX Workbench, select an Lx-FcuL device.

2. Right-click the device and expand the Views menu item.

3. Select the LX-FCUL view.

4. Under the LONMARK Objects column, select the FanCoilObject.

5. Under the Wizards column, select the LX-FCUL Wizard.

6. Click Launch.

Figure 8: LX-FCUL Wizard View


Fan Coil Unit Controller Installation OverviewFigure 9 shows one possible installation of the Fan Coil Unit Controller. Inputs, outputs, ducts, and heating or cooling units have been marked for your convenience.

Note: Not all possible sensors are shown.

InputsThe Fan Coil Unit Controller has six universal inputs. You can set universal inputs through the configuration wizard. Universal inputs are configured as either:

• analog inputs sensing either current or voltage, or

• digital inputs or 10k ohm resistance inputs

Note: Because the Fan Coil Unit Controller can connect to a maximum of six sensors, you may want to connect some sensors using the LONWORKS network. All valid network inputs have priority over hardware inputs.

10k Ohm or Digital InputThe universal input, when configured as a 10k ohm or digital input, accepts a 10k ohm resistance input or a digital input such as a switch, also known as a cold contact.

HeatingFilter Cooling

Intake Air

DAT

Setp

oint

Offs

ett

Tem

pera

ture

Discharge Air

Conditioned Space

Occ

upan

cy

LX-FCUL Installation OverviewFan Coil Enclosure

DAT Discharge Air Temperature

Sensor Symbols

Temperature

Digital Input

Fan Coil Enclosure

3 Fan Speeds

Return Air

Figure 9: Possible Fan Coil Unit Controller Installation


The 10k ohm resistance range accommodates 10k ohm thermistors used in space temperature sensors or duct temperature sensors, or a 10k ohm potentiometer used as a setpoint offset.

Use the conversion table for resistance input of more than 10k ohm. The digital range accommodates the occupancy contact, bypass switch, and window switch.

See Figure 10 for wiring information for both 10k ohm resistance and digital inputs.

I1 I2 I3 I4 I6I5–+ + + + + +– –

ContactNO - NC

Thermistor

10k ohm

Both inputs are configured as 10k ohm or digital input. Configuration is done with either the LX-FCUL Wizard, or the Sensor wizard.

LX-FCUL-1

Figure 10: 10k Ohm or Digital Input


Analog InputsAnalog inputs include current inputs with a range of 4–20 mA, and voltage inputs with a range of 0–10 VDC.

4 to 20 mA Analog Input, Externally Supplied

Current inputs require a power supply either on the sensor or wired in series with the sensor. To construct the current input, a 500-ohm 0.25-watt resistor is placed across the controller’s input terminals. See Figure 11 and Figure 12.

Sensors and SwitchesThe following sensors and switches can be connected to the Fan Coil Unit Controller. See Table 3 for the sensor and switches preferred SNVT types.

+–

Resistor:500 Ω − ¼

Watt

LX-FCUL-1

-m

ASensor

180

I1 I 2 I 3 I4 I6I5–+ + + + + +– –

Internal 24 VDCpower supply

Controller sourceoutput 4 - 20 mA

24

0

= ohmΩ

Figure 11: Sensor Powered Analog Input

–+

Resistor:500 Ω − ¼

Watt

LX-FCUL-1

4–

20m

A

–+

24VDC

Sensor

180

I1 I2 I3 I4 I6I5–+ + + + + +– –

= ohmΩ

Figure 12: Externally Powered Analog Input


Bypass Contact InputIf the FCU Controller is in unoccupied or standby mode, a switch closure on the bypass contact input causes the controller to enter occupied mode for the period of time set as the bypass time.

Discharge Temperature InputUse the discharge temperature input to maintain the discharge air temperature between the minimum and maximum discharge air temperature.

The discharge temperature setpoint is determined with a linear equation between the minimum and maximum discharge air temperature and the terminal load. During a high heating demand, the discharge temperature setpoint moves to its maximum temperature. Conversely, for a high cooling demand, the discharge temperature setpoint moves to its minimum temperature. The discharge temperature is viewed in nvoDischAirTemp.

Fan Speed Selector Input

Fan speed selector provides the Fan Coil Unit Controller with the ability to select up to three different fan speeds.

Fan State Input

The fan state input detects whether one of the three fan speeds is ON or OFF. If the fan state input does not correspond with one of the fan outputs for a time period known as the alarm delay, then an alarm becomes active. If the fan state input is OFF, while one of the fan outputs is ON, then equipment requiring air circulation remains OFF or does not modulate.

Note: All outputs except for the fan are disabled when the fan state is OFF.

Mode Selector Input

Mode selector enables selection of different modes of operation by means of an analog signal such as resistance, voltage, or current input.


The modes of operation available for selection from mode selector input are auto, heat, cool, fan only, and OFF. Table 2 describes the modes of operation.

Occupancy Input

Use the switch closure on the occupancy input to set the Fan Coil Unit Controller to occupied mode. The FCU Controller exits occupied mode when the switch is opened. Unless the controller is in bypass mode, the occupied contact does not function if the network variables nviOccCmd and nviOccManCmd are set to unoccupied.

Setpoint Offset InputThis input provides a means of varying the setpoint during occupied and standby modes. The values from this input are added to the pair of active setpoints. See the Calculating the Space Temperature Setpoint section.

Space Temperature InputThe FCU Controller uses the space temperature to control heating or cooling operations. One of the following inputs must be present for the controller to work:

• space temperature

• nviSlave

The space temperature sensor can be a 10k ohm thermistor, or provide a voltage or current input to the board.

Table 2: Modes of OperationMode DescriptionAuto Operates according to its setpoints and scheduled occupancy states; this means

that the Fan Coil Unit Controller controls heating, cooling, duct pressure, and the fresh air damper, according to the setpoints and the configuration properties you enter. The Fan Coil Unit Controller switches between unoccupied, occupied, standby, and bypass modes according to its schedule, and between the occupancy and bypass contacts if these contacts are present.

Heat Operates according to the heating setpoints in heating mode only. The heating setpoint may change as the controller switches scheduled states. The fan is ON when heating is ON; the fan is OFF at other times unless configured as ON during occupied periods. Cooling mode is unavailable.

Cool Operates according to the cooling setpoints in cooling mode only. The cooling setpoints may change as the controller switches scheduled states. The fan is ON when cooling is ON; the fan is OFF at other times unless configured as ON during occupied periods. Heating mode is unavailable.

Fan Only Configures the fan ON during the scheduled occupied state. Heating and cooling is not available. Fan configuration is found on the Fan-Valve window of the Fan Coil Unit Controller Configuration Wizard.

OFF Disables the control loop to OFF. All outputs are in the OFF state.


Water Temperature InputThe FCU Controller provides heating or cooling through a single, two-pipe system with a heating or cooling valve. If this system is used, the device must know the state, either hot or cold, of the available water. When the hardware water temperature input is used, the Fan Coil Unit Controller determines if the water is sufficiently hot or cold for heating or cooling.

• The networks inputs nviHotWater and nviWaterTemp are available for receiving the water state or temperature.

• If the water temperature is lower than the space temperature or nviHotWater state and value are zero, then the FCU Controller functions as if the water is cold.

• If nviHotWater state and value are not zero or the water temperature is higher than the space temperature, the controller functions as if the water is hot.

• Both inputs have priority over the hardware input; however, if both values are received, nviHotWater has priority over the nviWaterTemp.

Window Contact Input

If the Fan Coil Unit Controller is in occupied, bypass, or standby mode, and the fan coil is in operation (meaning that one of the fan speeds is ON), then a switch closure on the window contact input causes the FCU to enter unoccupied mode. All outputs are turned OFF while still respecting the unoccupied cooling and heating space temperature setpoints. Table 3: Sensor and Switch Preferred SNVT Type (Part 1 of 2)Sensor or Switch Preferred SNVT TypeBypass Contact Input SNVT_lev_disc SNVT_switch

SNVT_lev_occupancy

Discharge Temperature Input SNVT_temp SNVT_temp_f

SNVT_temp_p

Fan Speed Selector Input SNVT_lev_disc SNVT_switch

SNVT_lev_occupancy

Fan State Input SNVT_amp SNVT_lev_percent

SNVT_amp_ac SNVT_switch

SNVT_amp_f SNVT_lev_disc

Mode Selector SNVT_hvac_mode

Occupancy Input SNVT_lev_disc SNVT_switch

SNVT_lev_occupancy

Setpoint Offset Input SNVT_temp SNVT_temp_f

SNVT_temp_diff_p SNVT_temp_p

Space Temperature Input SNVT_temp SNVT_temp_f

SNVT_temp_p

Water Temperature Input SNVT_temp SNVT_temp_p

SNVT_temp_f


OutputsThe Fan Coil Unit Controller has five digital outputs (DO1, DO2, DO3, DO4, and DO5), and two analog outputs (AO1 and AO2). Descriptions of these outputs follow.

Analog OutputThe Fan Coil Unit Controller analog outputs are versatile and configured through the wizard as analog, digital, or PWM outputs. When an analog output is configured as a digital output, it supplies 60 mA at 12 VDC. This function is useful when driving relays external to the board. See Figure 13.

The characteristics of the analog outputs are described in Table 4.

Analog Output Protection

Analog outputs are protected by an auto-reset fuse with a maximum current capacity defined by the following two points:

• 100 mA at 68°F (20°C)

• 0 mA at 140°F (60°C)

Window Contact Input SNVT_lev_disc SNVT_occupancy

SNVT_switch

Table 4: Tri-Mode Analog Output CharacteristicsMode Maximum Current and Voltage Voltage RangeDigital 60 mA at 12 VDC (200 ohm load) 0–12 VDC

Analog 50 mA at 10 VDC 0–10 VDC (linear)

PWM 50 mA at 10 VDC 0 or 10 VDC

Table 3: Sensor and Switch Preferred SNVT Type (Part 2 of 2)Sensor or Switch Preferred SNVT Type

180

DO1 C DO2 C DO3 C DO4 C DO5 C AO1 AO2–

K

Connect a diode tothe relay terminal.(Ir=1 A at Vr=25 V)

12 VDC RelayMax load 200 ohm

Figure 13: Analog Output Driving an External Relay


Digital OutputsThe digital outputs of the FCU Controller use triacs to switch the output signal. Each digital output is capable of conducting 1 ampere.

Digital outputs function as a switch to control the current (Figure 14). The current source is separate from the transformers supplying the current for the controller.

The FCU Controller uses a half-wave power supply. Any other half-wave power supply that connects with the controller through the outputs or inputs must be in phase with the power supply of the controller.

Note: Do not share grounds between a full-wave and a half-wave power supply.

You can reverse any digital output scale by using the configuration wizard. Normally, ON is a 100% output; when the output is reversed, ON is a 0% output.

By using the FCU Controller object override command, you can override all digital outputs to a previously set value. The override values are set during the configuration process. The configuration wizard provides a menu for issuing object commands, including the override command. See the Object Manage section for more information.

Figure 14: Fan Coil Unit Controller Digital Outputs

DO1 C DO2 C DO3 C DO4 C DO5 C AO1 AO2–

Power Supply24 VAC

LC

Max. Current1A @ 24VAC


Staged OutputsWhen there are multiple heating or cooling outputs, you can organize the outputs into stages that turn on sequentially, one after the other. In general, heating or cooling stage (n) must be open for the period of time specified in the minimum heating period before heating or cooling stage (n+1) can turn on. For example, heating stage 1 must be open for the minimum heating period before duct heating stage 2 turns on. See Figure 15.

Output SelectionsThere are 24 possible output selections. Several output selections are dependent upon other output selections. For example, cooling 1–3 can be blocked depending on the setting of the reversing valve. See Table 5 for a description of outputs. Table 5: Output Selections (Part 1 of 2)Output Selection DescriptionFan Speed 1–3 These outputs provide digital fan speed control. See the Fan

Operation section for a detailed description of fan speed operation.

Heating Outputs 1–3 Heating outputs 1–3 are staged outputs that are turned ON after heating valve outputs, if any, are 100% open.

Cooling Outputs 1–3 Cooling outputs 1–3 are staged outputs that are turned ON after cooling valve outputs, if any, are 100% open.

Reversing Valve The reversing valve has two states. If the reversing valve is defined and is ON, then cooling outputs 1–3 act as heating outputs.

Heat Valve ON-OFF This output operates the digital heating valve.

Cool Valve ON-OFF This output operates the digital cooling valve.

Heat Cool Valve ON-OFF This output operates the digital heating-cooling valve according to the water temperature.

Heat Valve Open or Close These outputs operate heating floating valves.

Time

Minimum heating period



Hea

ting

Effo

rt

Stage 1 ON Stage 1 ON

Stage 2 ON

Stage 1 ON

Stage 2 ON

Stage 3 ON

Heating commanded to 100% ON at this time.

Stage 2 turns ON.

Stage 3 turns ON.

100%

Stage 1 turns ON.

Figure 15: Staged Outputs


Mode SelectionThe FCU Controller has several different operating modes. Each mode has a unique set of setpoints. Modes are initiated as a result of any one item in the following list:

• change of value in nviOccCmd

• change of value in nviOccManCmd

• occupied button press

• bypass button press

• window open/close contact

While in any mode, the controller can enter a heating or cooling state as required to maintain the space within the limits of the setpoints. Setpoints for each mode are shown in Table 6.

Network Variables Used for Mode Selection

The network variable nviOccCmd commands the FCU Controller to change modes according to the value of the variable. The value of nviOccCmd is changed by a schedule or other supervisory input.

Cooling Valve Open or Close These outputs operate cooling floating valves.

Heat Cool Valve Open or Close

These outputs operate heating-cooling floating valves according to the water temperature.

Fan Speed Modulate (FAN_SPEED_MOD)

This output provides a variable speed fan control output.

Heating Modulate (HEATING_MOD)

This output provides the modulated heating control output.

Heating or Cooling Valve Modulate(HEATING_VALVE_MOD)(COOLING_VALVE_MOD)(HEAT_COOL_VALVE_MOD)

These outputs provide modulated heating or cooling valve outputs.

Table 6: Values of nviOccCmd or nviOccManCmd and ModesIdentifier Fan Coil Unit Controller Mode SetpointsOC_OCCUPIED Occupied mode Occupied heat and cool

OC_UNOCCUPIED Unoccupied mode Unoccupied heat and cool

OC_BYPASS Bypass mode Occupied heat and cool

OC_STANDBY Standby mode Standby heat and cool

OC_NUL Invalid data Unoccupied heat and cool

Table 5: Output Selections (Part 2 of 2)Output Selection Description


You can manually command the FCU Controller to change modes through network variable nviOccManCmd. Because manual commands (commands entered by the operator) have priority over mode commands from a scheduler node, nviOccManCmd has priority over nviOccCmd. Both network variable inputs have priority over the occupancy contact or bypass button press. Table 6 shows possible values of nviOccCmd and nviOccManCmd.

The network variable nviOccManCmd has priority over nviOccCmd. Therefore, mode commands entered manually have priority over mode commands from a scheduler node. Both network variable inputs have priority over the occupancy contact or bypass button press. See Table 7 for a simplified list of priority levels.

Certain conditions must exist for the controller to be in either unoccupied or occupied mode. If nviOccCmd and nviOccManCmd are set to OC_NUL, OC_BYPASS, or OC_STANDBY (and the occupancy contact is OFF or unassigned), then the FCU Controller is in unoccupied mode. If nviOccCmd and nviOccManCmd are set to OC_NUL, OC_BYPASS, or OC_STANDBY (and the occupancy contact is ON), then the Fan Coil Unit Controller is in occupied mode. However, when you press the bypass button in either unoccupied or standby mode, it causes the Fan Coil Unit Controller to enter bypass mode.

When the window contact is ON, or nviEnergyHoldOff receives a value and a state different than zero, then the schedule is set to OC_UNOCCUPIED and nviEnergyHoldOff has priority over the window contact. The effect on the controller is to shut down the fan and all other mechanical equipment. For example, if the window is opened, an unoccupied room remains unheated ensuring that heat and energy are not lost.

Occupied ModeOccupied mode uses the occupied setpoints that you set in the configuration wizard and ensures the building environment is comfortable for building occupants.

Table 7: Priorities of Mode Changing InputsPriority Level1

1. Priority 1 is the highest.

Input Function

1 nviEnergyHoldOff enter unoccupied mode

2 Window Contact enter unoccupied mode

3 nviOccManCmd manual mode change

4 nviOccCmd scheduled mode change

5 Occupancy contact enter occupied mode

6 Bypass button press enter bypass mode and start the bypass timer


Starting Occupied ModeOccupied mode begins as result of one of the following events:

• A command is received on nviOccManCmd or nviOccCmd. To modify these network variables, use a computer connected to a network to manually command nviOccManCmd, or use the building schedule to modify nviOccCmd.

• The occupancy switch is closed when both nviOccCmd and nviOccManCmd are set to OC_NUL, OC_BYPASS, or OC_STANDY.

Ending Occupied Mode

The Fan Coil Unit Controller exits occupied mode when any one of the following events occur:

• Another state is commanded through network variable nviOccManCmd. This method is used for a manual override from a computer.

• Another state is commanded through network variable nviOccCmd. This method is used with a scheduler node.

• The occupancy contact opens while nviOccCmd and nviOccManCmd are set to OC_NUL, OC_BYPASS, or OC_STANDY.

• The window contact is closed, or nviEnergyHoldOff receives a value and a state different from zero; the occupancy status sets to OC_UNOCCUPIED.

Unoccupied ModeThe FCU Controller uses unoccupied mode when the building is empty overnight or over a weekend. By allowing the space temperature to vary greater than it does while in occupied mode, unoccupied mode reduces cost. Despite the greater temperature variance, unoccupied mode maintains the building close enough to the occupied range of temperature ensuring it is made ready quickly for occupancy on a regular schedule.

Starting Unoccupied Mode

Unoccupied mode uses the unoccupied setpoints that you set in the configuration wizard. It cannot begin if the Fan Coil Unit Controller is currently in bypass mode. Unoccupied mode begins as result of one of the following events:

• The unoccupied state is commanded by nviOccManCmd. This method could be used for a manual override.

• A schedule change by a supervisory node sets the network variable nviOccCmd to OC_UNOCCUPIED. Because nviOccManCmd has priority over nviOccCmd, nviOccManCmd must be set to OC_NUL for the schedule change to occur.

• The occupancy contact is open or not assigned and both nviOccManCmd and nviOccCmd are set to OC_NUL. This method is used to manually switch between occupied and unoccupied modes.


• The window contact is closed or nviEnergyHoldOff XE (nviEnergyHoldOff) receives a value and a state different from zero; the occupancy status is set to OC_UNOCCUPIED.

During the unoccupied state, the controller heats or cools the space as required to maintain the temperature within the limits set by the unoccupied setpoints.

Note: In unoccupied mode, the setpoint offset from input or network variable has no effect on the effective setpoint.

Ending Unoccupied Mode

Unoccupied mode ends when any one of the following events occur:

• Another mode is commanded by nviOccCmd while nviOccManCmd is set to OC_NUL. This method is used to implement a schedule.

• Another mode is commanded by nviOccManCmd. This method is used as a manual override.

• The bypass button on the space temperature sensor is pressed. This button short-circuits the sensor.

• The occupied contact is closed and both nviOccCmd and nviOccManCmd are invalid.

• The bypass contact input is pressed.

• The window contact is opened or nviEnergyHoldOff receives a value or a state equal to zero. The Fan Coil Unit Controller enters the currently scheduled mode or the mode currently commanded by the occupancy contact.

Bypass ModeBypass mode uses the occupied setpoints to provide a comfortable environment when individuals are using a space outside of the normal scheduled time.

Bypass mode is temporary. The duration of bypass mode is a time period called bypass time that is set on the General Settings configuration dialog box.

When the Fan Coil Unit Controller enters bypass mode, the bypass time period begins; when the bypass time period ends, the Fan Coil Unit Controller exits bypass mode.

Starting Bypass ModeThe Fan Coil Unit Controller can be commanded to enter bypass mode by either nviOccManCmd or by nviOccCmd. See the Network Variables Used for Mode Selection section for more information.

The Fan Coil Unit Controller enters bypass mode when any of the following occurs during unoccupied or standby mode:

• The bypass button on the space temperature sensor is pressed.

• The bypass contact is closed.


Note: The Fan Coil Unit Controller does not enter bypass mode if the bypass time is set to zero.

Ending Bypass Mode

Bypass mode ends as a result of one of the following events:

• Occupancy contact is closed; the Fan Coil Unit Controller exits bypass mode and enters occupied mode.

• The window contact is closed or nviEnergyHoldOff XE (nviEnergyHoldOff) receives a value and a state different from zero; the occupancy status is set to OC_UNOCCUPIED.

• The bypass timer expires; the Fan Coil Unit Controller enters the currently scheduled mode, or the mode currently commanded by the occupancy contact.

If bypass mode ends when the bypass timer expires, and nviOccManCmd is set to OC_BYPASS, the controller sets nviOccManCmd to OC_NUL. This scenario returns occupancy control to a scheduler using network input nviOccCmd or to an occupancy contact.

If nviOccManCmd is not set to OC_NUL, it has priority over nviOccCmd and the occupancy contact.

Standby ModeIn standby mode, the space temperature is allowed a greater amount of variance than in occupied mode. Like unoccupied mode, the space is maintained at a temperature close enough to the occupied setpoints, ensuring it is ready for occupancy quickly. Standby is intended for areas such as meeting rooms that are intermittently occupied during the normal working day. Standby mode setpoints are entered during the Fan Coil Unit Controller configuration.

Starting Standby ModeThe Fan Coil Unit Controller enters standby mode as a result of either:

• a scheduler node writing to nviOccCmd

• an operator writing a command to nviOccCmd and/or nviOccManCmd

Note: Any commands by nviOccCmd can be overridden by nviOccManCmd as shown in Table 6. For nviOccCmd to be effective, nviOccManCmd must be set to OC_NUL.

Ending Standby ModeThe Fan Coil Unit Controller exits standby mode when any of the following occurs:

• The bypass button on the temperature sensor is pressed or the bypass contact input is ON. These events initiate bypass mode.

• The occupancy contact is closed. This event initiates the occupied mode.


• The network variable nviOccManCmd is set to another value by an operator or program.

• The network variable nviOccManCmd is set to another value while nviOccManCmd is set to OC_NUL. Use this method to follow a schedule.

• The window contact is closed or nviEnergyHoldOff receives a value and a state different from zero, the occupancy status is set to OC_UNOCCUPIED.

Slave ModeThe Fan Coil Unit Controller enters slave mode when nviSlave (SNVT_hvac_status) is bound to the nvoUnitStatus of another fan coil. The FCU Controller attempts to follow the heating or cooling demand of the other unit.

State Selection and DescriptionThe Fan Coil Unit Controller enters occupied, unoccupied, standby, and bypass modes depending on the schedule, and other inputs such as the bypass contact switch. Within each mode, the FCU Controller can enter various states such as heating, cooling, and morning warm-up.

Supervisory Control and SchedulingThe network variable nviApplicMode coordinates the Fan Coil Unit Controller with a supervisory control such as a schedule or a Human Machine Interface (HMI). The variable nviApplicMode is a SNVT_hvac_mode and must be bound to a network variable output that is also a SNVT_hvac_mode from the HMI, supervisory control, or air handler.

When this connection is complete, the HMI or supervisory control sets the Fan Coil Unit Controller to different states through nviApplicMode.

For more information about nviApplicMode, see Table 27.

Calculating the Space Temperature SetpointWhen nviApplicMode is set to HVAC_Auto, the space temperature setpoint determines whether the unit enters a cooling or heating state. Space temperature setpoint calculations are addressed before state descriptions to ensure your understanding of how the state is selected.

When you configure the Fan Coil Unit Controller, you enter three pairs of setpoints for the four operating states. Because bypass mode uses the same setpoints as occupied mode, there are only three setpoint pairs: occupied, unoccupied, and standby. They are stored in SCPTSetPnts.


The FCU Controller selects a pair of setpoints as the active setpoints depending on the current mode. After this, the active setpoints are modified by the following variables:

• nviSetPoint

• nviSetPtOffset

• Setpoint Input

The Effect of nviSetPoint on the Active SetpointsThe variable nviSetPoint allows you to change the setpoint using LON tools. If nviSetPoint has a valid value, and if the mode is standby or occupied, then the two active setpoints are calculated as follows:

The value of Setpoint_move and Setpoint Offset is added to each member of the active setpoint pair. For the following example, the Setpoint Offset value is considered to be zero.

Example: If nviSetPoint is equal to 75°F (23.9°C) and the two setpoints are 72°F (22.2°C) and 68°F (20°C), then:

The two setpoints become 77ºF (25ºC) and 73ºF (22.8°C).

Note: The network variable nviSetPoint is inactive in unoccupied mode.

The Effect of a Setpoint Offset on the Active Setpoints

Setpoint offset is added to the pair of currently active setpoints. For example, if the setpoints are 72°F (22.2°C) and 68°F (20°C), and the setpoint offset is 2F° (1.1C°), then the value of the setpoints with the offset are (72+2)°F (22.2°C+1.1°C) and (68+2)°F (20°C+1.1°C).

The two possible sources of a setpoint offset are the network variable nviSetPtOffset or a hardware input. Input nviSetPtOffset allows you to change the value of the setpoint offset.

Hardware inputs are secondary to nviSetPtOffset. For the hardware input to be active, the value of nviSetPtOffset must be invalid, and occupancy mode cannot be unoccupied. The invalid value for nviSetPtOffset is 621.806°F (327.670°C). Connect the input to a 10k ohm potentiometer in the conditioned space.

Note: The network variable nviSetPtOffset has priority over the hardware input.

( )Setpoint_ move = −

+nviSetPo

occupied cool occupied heatint

_ _2

OffsetSetpoint oveSetpoint_mointsActiveSetppointsActive_Set ++=

( )2687275oveSetpoint_m FF °+

−°=

F°= 5oveSetpoint_m


Cooling StateThe Fan Coil Unit Controller controls the following cooling types:

• digital cooling

• staged digital cooling

• cooling using heat pump

• floating valve cooling

• modulated valve cooling

The FCU Controller uses mechanical cooling. This method uses chiller units and cooling coils to remove heat from the building.

Mechanical Cooling

The FCU Controller turns the mechanical cooling outputs ON when all of the following conditions occur:

• The fan speeds 1, 2, or 3 are ON, or fan speed modulation is at the minimum speed.

• All heating outputs have been OFF for the minimum amount of time defined by UCPTchngeOverDelay or Change Over Delay on the Heating-Cooling Configuration window.

• nviApplicMode must be set to HVAC_AUTO or HVAC_COOL.

• The space temperature input data must be valid, or the Fan Coil Unit Controller must be slaved to another unit.

• There must be a cooling demand. A cooling demand results from a comparison between the space temperature and the active cooling setpoint.

• If a floating cooling valve is used, then one output must be COOL_VALVE_OPEN and another output must be COOL_VALVE_CLOSE.

The water used for cooling and heating operations must be cold for any outputs, configured as such, to work:

• HEAT_COOL_VAVLE_ON_OFF

• HEAT_COOL_VAVLE_CLOSE

• HEAT_COOL_VAVLE_OPEN

• HEAT_COOL_VAVLE_MOD

The water is cold when the water temperature is colder than the room temperature, or when the nviHotWater received value or state is zero.

Note: nviHotWater has priority over the water temperature read from either the input sensor or nviWaterTemp.


Cooling DemandCooling demand results from either of the following:

• the error between the active cooling setpoint and the space temperature

• nviSlave

Cooling Output SequenceDuring an increasing cooling demand, the first fan stage turns ON, which enables all mechanical cooling equipment. After this, fan speed two and three turn ON. During a decreasing cooling demand, fan, and mechanical cooling equipment are disabled in the reverse order. However, fan speed one can remain ON in occupied mode because of the Always On option. See the Cooling Terminal Load section for more information.

If a cooling valve output is configured, then cooling outputs 1 - 3 turn ON only after valve outputs are at 100%.

Cooling outputs 1 - 3 are staged outputs. See the Staged Outputs section for more information.

Ending the Cooling State

Cooling outputs shut off when the bias reaches a negligible amount. However, if the PID loop control has accumulated bias during the cooling stage, cooling outputs may not shut off when the space temperature reaches the setpoint.

Heating StatesThe Fan Coil Unit Controller controls the following heating types:

• digital heating

• staged digital heating

• heat pump heating

• floating valve heating

• modulated valve heating

The Fan Coil Unit Controller turns the heating outputs ON when the following conditions are present:

• The fan must be ON.

• All cooling outputs must be OFF for the time period defined as a Change Over Delay on the Heating-Cooling Configuration window, unless another input is configured as a reversing valve. If another input is configured as a reversing valve, the first stage of cooling turns ON at the same time as the reversing valve. See the Cooling Outputs Used to Heat section.

• The network variable nviApplicMode must be set to HVAC_AUTO or HVAC_HEAT.


• The FCU Controller must receive the space temperature and terminal loads through nviTerminalLoad, or it must be slaved to another unit through nviSlave. The FCU Controller can receive space temperature through a hardware input or through nviSpaceTemp.

• There must be heating demand. See the Heating Demand section.

• If a floating heating valve is used, one output must open the heating valve and another output must close the valve.

The water source used for the heating coils must be hot for the following control outputs to work:

• HEAT_COOL_VALVE_ON_OFF

• HEAT_COOL_VALVE_OPEN

• HEAT_COOL_VALVE_CLOSE

• HEAT_COOL_VALVE_MOD

The water is hot when the water temperature is warmer than the room temperature, or when nviHotWater receives a value and state different from zero.

Note: The nviHotWater variable has priority for the water temperature either from the input sensor or nviWaterTemp.

Heating Demand

A heating demand results from any one of the following:

• an error between the active heating setpoint and space temperature

• nviSlave

If heating demand is taken from nviSlave, then the Fan Coil Unit Controller operates in slave mode and receives the heating demand from another unit.

Heating Output Sequence

Heating outputs 1 - 3 are staged outputs. Heating output 1 is the first heating stage in the stage sequence. See the Staged Outputs section for more information.

Heating outputs 1 - 3 and Heating_Mod do not turn ON until all heating valve outputs are at 100%.

Cooling Outputs Used to HeatYou can use cooling outputs 1 - 3 to heat if another output is configured as a reversing valve. The reversing valve turns ON at the same moment as the first stage of cooling.

If cooling outputs are used to heat, then heat outputs 1 - 3 and Heating_Mod do not turn on until the cooling outputs are at 100%.


Ending the Heating StateThe heating state ends when the demand for heating ceases, and the first heating stage (if any) has operated for more than the minimum heating period.

If the PID loop control has accumulated bias during the heating stage, heating outputs may not shut off when the space temperature reaches the setpoint. The output shuts off when the bias reaches zero.

Fan OperationThree fan speeds are available in the FCU Controller. Fan speeds are started according to the heating or cooling demand and according to the outputs set in the Fan Coil Unit Controller Configuration Wizard. Normal operation sequence begins with the FCU Controller commanding the first fan speed to turn ON. After this, the FCU Controller starts or modulates all cooling and heating outputs to their maximum capacity according to their respective demands. Finally, all other fan speeds are started according to their respective demands.

If the fan option Always On in occupied mode is selected and the occupancy status is OC_OCCUPIED or OC_BYPASS, the first fan speed is ON. Otherwise, the first fan speed starts according to a cooling or heating demand.

Fan speeds two and three are controlled by a cooling and heating demand. However, heating outputs and cooling outputs must be configured for these fan speeds to start.

Fan speeds two and three increase cool or hot air volume in the room. For example, during a heating demand, it would not be appropriate to increase the air volume if the discharge air is not reheated. This situation creates discomfort for room occupants as they receive colder air.


The minimum time that any fan speed must be ON before it turns OFF, and the minimum time that any fan speed must be OFF before it turns ON, are both set in the Fan-Valve window of the FCU Controller configuration wizard. Enter a value in the ON/OFF period field on that window. See Figure 16.

Terminal LoadTerminal load describes the energy consumption of a Fan Coil Unit Controller for both heating and cooling operations. The network variable nvoTerminalLoad transmits the terminal load of the controller over the network.

Figure 16: Fan-Valve Configuration Window


Heating Terminal LoadNegative terminal load numbers represent the heating terminal load. Heating effort increases as the terminal load decreases. At 100% heating effort, the terminal load is -100% (Figure 17).

Term

inal

Loa

d

Time

Heating Effort

Heating Terminal Load

0%-5

0%-1

00%

0%10

0%50

%

Figure 17: Heating Terminal Load


Cooling Terminal LoadPositive numbers represent the cooling part of terminal load. The terminal load increases as cooling effort increases. At 100% cooling effort, the terminal load is 100% (Figure 18).

Term

inal

Loa

d

Time

Cooling Effort

Cooling Terminal Load10

0%50

%0%

100%

0%50

%

Figure 18: Cooling Terminal Load


Networking OperationsThis section describes the operations that occur only as a result of network connections and provides a description of network variable properties.

Slave OperationThe FCU Controller follows the demands of another fan coil unit controller if nviSlave is bound to the nvoUnitStatus of another fan coil unit. The network variable nviSlave is type SNVT_hvac_status.

Load SheddingIf the Fan Coil Unit Controller receives an input on nviShedding, it reduces its output. As the value of nviShedding increases, the FCU Controller further reduces its output. For example, if nviShedding is at 25%, heating and cooling outputs do not exceed 75%.

Shedding is stopped if frost protection is enabled, and space temperature falls under 46°F (8°C). The network variable nviShedding is type SNVT_switch.

Setting up Network ConnectionsThe Fan Coil Unit Controller interfaces through the LON network to controllers and software using the LonTalk® protocol.

Whereas the FCU Controller can function without a network connection, the network variables sent and received over the LON by the controller can affect all of its operations.

Network Outputs

The network variables have several important attributes in common. These attributes include Heartbeat, Send on Delta, and Throttle.

Table 8 defines the network variable attributes. Table 9 describes the network inputs. Table 8: Network OutputsAttribute DescriptionHeartbeat Heartbeat is the maximum amount of time that must pass before the network

variable automatically transmits. The presence of the heartbeat attribute indicates that functions are proceeding normally. Failure to receive a signal at the other node within a heartbeat interval causes an alarm message to be sent over the network.Heartbeat is like a countdown timer. Only when the heartbeat timer reaches zero is the heartbeat message sent. Every time that a message is sent, the Heartbeat timer resets to the full heartbeat value.Heartbeat signals are not always sent. If the monitored data changes more than is required by the Send on Delta setting within a shorter period of time than the heartbeat, the data is sent on the network and the heartbeat message is not sent. Instead, the heartbeat timer is reset and begins to count down again.Heartbeat provides a method of ensuring that points have not lost connection and that the network is functioning. Whereas throttle restricts how often messages are sent, heartbeat ensures that messages are sent regularly. Heartbeat is disabled by setting it to zero.


Optimum StartOptimum Start prepares the space for occupancy in advance of the occupied period. If you start heating or cooling at the optimum time before the occupied period begins, the FCU Controller provides a comfortable space that is ready for occupancy without wasting energy. You can enable Optimum Start on the Heating-Cooling window of the Fan Coil Unit Controller Configuration Wizard. Select the boxes labeled Enable Optimum Start for heating and Enable Optimum Start for cooling.

For gathering data, the FCU Controller maintains statistics that compare the outside temperature to the time required for the space to reach the occupied setpoints. The FCU Controller uses these statistics to calculate the length of time required for Optimum Start.

Because the Optimum Start time is calculated every day for the current outside air temperature, it is much more energy efficient than simply starting the occupancy period before the actual arrival of occupants.

Send on Delta Send on Delta causes a message to be sent when the monitored data changes by a previously set proportion. Send on Delta restricts extraneous network noise by allowing only signals that indicate a meaningful amount of change.If the monitored data does not change for a period of time equal to the heartbeat interval, the data is sent as a heartbeat signal.

Throttle Throttle sets the minimum update period. Throttle acts as a limit on excessive network traffic. If the value of a point on the network is constantly fluctuating at a rapid rate and is set to Send on Delta, the network is flooded by data from that point. Throttle prevents the variable from transmitting more than once every minimum update period regardless of how many fluctuations have occurred during that period. For example, rapid motion of the damper could drastically increase network traffic. Damper oscillations could also cause network traffic problems if data were sent on every cycle of oscillation. Throttle can prevent network congestion in either of these cases by limiting the number of sends per time interval to a meaningful number.Throttle units are in seconds. The larger the throttle number, the less frequently the network variable is transmitted. You can disable throttle by setting it to zero.

Table 9: Network InputsAttribute DescriptionHeartbeat The Heartbeat effect on a network input is set to the maximum time period

that the network variable waits for a message before entering the heartbeat failure state. When a heartbeat failure state is entered, the value becomes invalid and an alarm is sent.

Persistent When the network variable is marked as persistent, the value is written to Electrically Erasable Programmable Read-Only Memory (EEPROM). Once written to EEPROM, the network variable value is preserved through power outages and resets. Every time a new network variable value is received, the new value is written into EEPROM.Because EEPROM can only accept a limited number of data writes, be careful how you use the persistent attribute. See the Persistent Network Variables section for more information.

Table 8: Network OutputsAttribute Description


For setup, enter a value in the Maximum start time box to limit the Optimum Start time period. Optimum Start begins no sooner than the Maximum start time before the occupancy change. For example, if the space enters the occupied mode at 8:00 A.M. and the Maximum start time is 30 minutes, then Optimum Start does not begin until 7:30 A.M. at the earliest. Of course, Optimum Start can still begin at any time that is less than 30 minutes before 8:00 A.M.; for example, 7:41 A.M.

When statistics are not available, Optimum Start has two options. The first option starts heating or cooling when the space occupancy changes. The second option allows Optimum Start to use the Maximum start time. To enable this feature, select the box labeled Use maximum time if no statistics on the Heating-Cooling configuration window.

Regardless of which setting you choose, the first samples are saved when the FCU Controller does not have any statistics; these samples include the outside air temperature and the time required to reach the setpoint. Each day, Optimum Start uses the time recorded from the previous day’s sample. For example, if the Fan Coil Unit Controller recorded that the space reached occupied setpoint in 25 minutes the first day, then on the second day the FCU Controller would begin Optimum Start 25 minutes before occupancy. If a maximum start time has been entered, the FCU Controller may use a value derived from the samples that is less than the maximum start time. However, the controller does not use a start time that is greater than the maximum start time value.

On the third day, the FCU Controller has two samples stored, and uses the two samples to calculate the Optimum Start time taking into consideration the current outdoor temperature. From this point, all Optimum Start times are statistically calculated by the FCU Controller using its saved samples.

Requirements for Optimum StartThe next state and time to the mode must be defined in advance. There must be a scheduler, and the schedule must be properly bound to the Fan Coil Unit Controller using nviOccCmd.

In addition, the network variable nviOccCmd must be set to SNVT type SNVT_tod_event. You can do this using the Changeable Nv Manager view of the device in FX Workbench. See Change Network Variable Type for details.

Because the Optimum Start is based on statistics calculated from the room temperature and the outside air temperature, nviOutdoorTemp must be connected to a network variable.

The PID LoopPID loops provide precision control over space temperature and ventilation.

The control loop modulates its output to drive its input to a setpoint. The control loop inputs are the sensor readings of the temperature. The outputs are, for example, the fan speeds, and the heating or cooling outputs.


The difference between the input and the setpoint is called the error. The controller output is a function of the error.

The Fan Coil Unit Controller provides PID control settings through its configuration wizard. Figure 20 shows the PID window.

Controller

SpaceSensor Output

Inpu

t

Out

put

Setpoint

Figure 19: PID Controller with Input, Setpoint, and Output

Figure 20: PID Configuration Window


For both space temperature and discharge temperature, there are settings for proportional, integral, and derivative gains. Each of these gains contributes to the final output as shown in Figure 21. They are discussed separately in the following sections.

ProportionalProportional control provides an output that is proportional to the error. The error is multiplied by a number called the gain. The result is used to produce the output.

For example, if the room temperature is 69°F (20.6°C) and the setpoint is 72°F (22.2°C), then the error is 3°F (1.7°C). If the gain is equal to 10% per °F, then the output is 30% of the maximum output value.

IntegralThe integral component has a gain and time setting. These work together to remove errors that accumulate over time.

GainThe integral gain is similar to the proportional gain. The error is multiplied by the value you entered as integral gain. If the gain is equal to 5% per °F and the error is 2°F (1.1°C), the integral output is 10% of the maximum possible output signal.

TimeThe integral gain differs from the proportional gain in that the output is increased the longer that the error persists. This situation occurs because the product of the error multiplied by the integral gain is periodically added to the output. When you enter the time, you are entering the length of the time period over which the error is added.

Proportional Integral Derivative Total Output+ + =

Figure 21: Total Output Composed of P, I, and D Components


How It Is UsedConsider a building in a cold climate where the temperature of a certain space is never quite warm enough. A log of the temperature of this space would produce a graph such as Figure 22.

As Figure 22 illustrates, the temperature never quite falls low enough to turn on the proportional heat.

However, with a proportional integral controller, the error would accumulate over time. Periodically, a portion of the error would be added back into the error. Error would accumulate and would finally be great enough to turn on the heat. See Figure 23.

DerivativeDerivative control recognizes and responds to sudden changes in the input value.

Whereas integral control is able to correct errors that persist over time, derivative control can respond quickly to sudden changes.

Tem

pera

ture

Time

Setpoint

Heat is ON

Heat is OFF.

Space Temperature

8:00 8:30 9:0010:00

Figure 22: Never Quite Warm Enough:Using Only a P Controller

Tem

pera

ture

Time

Setpoint

Heat is ON

Heat is OFF

Heat is ON

8:00 8:30 9:0010:00

Error accumulates

Space Temperature

Figure 23: Heating Using a PI Controller


Consider a graph of temperature over time. Because the derivative of a function is the rate of change of the function, the derivative of temperature over time is the rate of change of the temperature per unit time. For example, rate of change could be degrees per minute.

Derivative control opposes the rate of change. For example, consider a hospital lobby in the arctic. Because the lobby changes temperature often, it has its own local heaters that are controlled by a PID loop. Every time the hospital doors open, the temperature in the lobby quickly decreases. This sudden drop in temperature is a considerable rate of change. This considerable rate of change is opposed by the derivative control. The derivative control increases the output of the PID loop that increases the output of the heaters. As the lobby temperature becomes closer to the setpoint, the derivative control output decreases to zero as the lobby temperature reaches its setpoint.

Gain

The derivative gain is the amplification of the derivative output. The gain is measured as a percentage per unit of change where a unit is a Centigrade or Fahrenheit degree. If 50 is entered into the Gain field, then each unit of error causes a 50% increase in derivative control output.

Time

Derivative control normally responds to measured values rather than to the actual direct input. By doing so, the derivative control is prevented from creating large short spikes in the controller output. The spikes are the derivative control response to sudden increase or decrease in error due to setpoint changes.

Time refers to the period between measurements of the input. If the time is set to 3 seconds, and the gain is 25%/°F, then the derivative output is 25% of the error for each degree of error and recalculates every 3 seconds.

DeadbandThe deadband is a range of input values close enough to the setpoint that their effect is unnoticeable. The setpoint is the center of the range of values. While the input lies within the deadband, deviations from the setpoint are not calculated as errors.


If the deadband is equal to 1/2 x , then the deadband extends from the setpoint - 1/2 x to the setpoint + 1/2 x . The maximum amount of deviation allowed is ± 1/2 x . See Figure 24.

When you use deadbands, it reduces mechanical wear and tear on moving parts because the mechanical parts no longer oscillate to accommodate trivial errors.

Setpointx

0.5x

0.5xInput

As soon as the input exceeds the deadband, the PID loop will sense an error at its input. Whatever the PID outputs will do next, depends on the PID loop settings.

As long as input stays within the deadband, the error will be zero. As long as the error is zero, the PID loop will not change its output signal.

Deadband with Value of x

Mag

nitu

de

Time

Deadband Limits

Deadband Limits

Figure 24: Effect of Deadband upon PID Loop Error


Alarm OperationShown in Figure 25, the Alarms Configuration window of the Fan Coil Unit Controller Configuration Wizard provides user-set alarms. You can configure and enable these alarms to match the requirements of your current site. User-set alarms are available for the following control points:

• space air temperature

• discharge air temperature

• fan alarm

In addition to the preceding user-set alarms, other alarms are provided. These include:

• heartbeat alarms for network inputs

• disconnect alarms for sensor points

Figure 25: Alarm Configuration Window


Alarm FeaturesFCU Controller alarms have a number of features that enable you to automatically and carefully monitor critical system information. Many of these features are visible in Figure 26.

Table 10: Alarm Features (Part 1 of 2)Feature DescriptionMonitored Variable Displays the network variable or control point that is monitored by the

alarm. For example, if you have an alarm that sends a message whenever a space temperature deviates too far from the setpoint, then the monitored variable is the space temperature.

Alarm State Enables when a monitored variable has a value that causes an alarm.

Alarm Offset Displays the amount that the monitored variable can deviate from the setpoint before entering the alarm state. See Figure 26. An offset causes the alarm to become active when the value of the monitored variable is greater than or less than the range of values equal to the setpoint ± offset. Alarms that use an alarm offset are often called deviation alarms.

Alarm Delay Displays the period of time that the monitored variable must be in the alarm state before an alarm message is generated. See Figure 26 and Figure 27.

Space Temp C

°

Features of a Deviation Alarm

Setpoint2220

15

25

2.0

C°

2.0

C°

Monitored Variable

Upper limit of Offset

Lower limit of Offset

Monitored variable exceeds value of offset + setpoint at this time.

An alarm message is not sent as the monitored variable is in the alarm state for less time than the value of the alarm delay.

Monitored variable enters alarm state at this time.

Alarm message is sent here after the expiration of the alarm delay.

Time

Offset = 2C°Alarm Delay = 10 minutes

10.0 min

10.0 min

Figure 26: Space Temperature Alarm


Alarms are transmitted using the network variables nvoFCalarm and nvoUnitStatus.

A number of alarms respond to the timing of network variables. Some of these are called heartbeat alarms because they respond to the heartbeat value. The heartbeat is the maximum length of time that can occur between transmissions of a variable on the network. If this time is exceeded, an alarm sounds.

Alarm TypesThe FCU Controller uses four types of alarms. Table 11 describes these alarm types.

Alarm ProcedureWhen an alarm condition occurs, the following changes take place:

• The appropriate bits of nvoStatus and nvoFCalarm are set.

• The in_alarm field of nvoUnitStatus is set to 1.

• The network variable nvoUnitStatus transmits information about the fan coil object.

The following text sorts the alarms by type, describes the conditions that generate an alarm, and organizes the associated bits of the nvoStatus and nvoFCalarm into a table.

Alarm Low Limit Displays a value that is less than the setpoint. When the monitored variable becomes equal to or less than the alarm low limit, an alarm message is transmitted over the network. Alarms that use a low limit are often called low limit alarms. See Figure 27.

Alarm High Limit Displays a value that is greater than the setpoint. When the monitored variable becomes equal to or greater than the alarm high limit, an alarm message is transmitted over the network. Alarms using high limits are often called high limit alarms. See Figure 27.

Table 11: Alarm TypesAlarm Type DescriptionDigital Alarms Monitors the state of digital network variables or hardware inputs. Digital

alarms can also indicate when digital network variables differ in state. For example, the fan output and the fan state should always be the same. If they differ, a digital alarm transmits a message on the network.

High Limit Alarms Reports when an analog network variable or hardware input is greater than a user-set value, called a high limit.

Low Limit Alarms Reports when an analog network variable or hardware input is less than a user-set value, called a low limit.

Deviation Alarms Reports when a monitored analog value deviates from its setpoint by more than a user-set value, known as an alarm offset.

Table 10: Alarm Features (Part 2 of 2)Feature Description


The alarm types are:

• heartbeat alarms

• disconnect alarms

• status alarms

• user-set alarms

Heartbeat Alarms

Heartbeat time values are set on the Network Input dialog boxes of the Fan Coil Unit Controller Configuration Wizard, or by modifying SCPTmaxRcvTime.

The column heading Bit # refers to the Bit Number of nvoFCalarm. The column programmatic name refers to the programmatic name of nvoFCalarm with the format type UNVT_fc_alarm that relays the status of the object. If a heartbeat alarm turns ON, a communication failure alarm sounds and Bit #13 of nvoStatus, programmatic name comm_failure, turns ON.

Supply Tem

p C°

Features of an Alarm Using High and Low Limits

Setpoint2220

15

25

Monitored variable falls below lower limit.

An alarm message is not sent as the monitored variable is in the alarm state for less time than the value of the alarm delay.

Monitored variable enters alarm state at this time.

10.0 min

Alarm message is sent at this time after the expiration of the alarm delay.

Time

18

Monitored Variable

Lower Alarm Limit = 18°CUpper Alarm Limit = 24°CAlarm Delay = 10 minutes

10.0 min

Upper Alarm Limit

Lower Alarm Limit

Figure 27: Discharge Temperature Alarm


Disconnect AlarmsThe column heading Bit # refers to the Bit Number of nvoFCalarm. The column programmatic name refers to the programmatic name of nvoFCalarm with the format type UNVT_fc_alarm that relays the status of the object. If a disconnect alarm turns ON, an electrical fault alarm sounds and Bit #11 of nvoStatus (programmatic name electrical_fault) turns ON.

User-Set AlarmsThe column heading Bit # refers to the Bit Number of nvoFCalarm. The column programmatic name refers to the programmatic name of nvoFCalarm with the format type UNVT_fc_alarm that relays the status of the object. If a user-set alarm turns ON, an out of limits alarm sounds and Bit #4 of nvoStatus (programmatic name out_of_limits) turns ON.

Table 12: Heartbeat AlarmsMonitored Point

Monitored Variable

Delay Time Bit#

Programmatic Name

Space Temperature

nviSpaceTemp SCPTmaxRcvTime 0 nviSpaceTempHeartBeat

Application Mode nviApplicMode SCPTmaxRcvTime 1 nviApplicModeHeartBeat

Setpoint Offset nviSetPtOffset SCPTmaxRcvTime 2 nviSetPtOffsetHeartBeat

Occupancy Command

nviOccCmd SCPTmaxRcvTime 3 nviOccCmdHeartBeat

Water Temperature

nviWaterTemp SCPTmaxRcvTime 4 nviWaterTempHeartBeat

Water Temperature State (Hot/Cold)

nviHotWater SCPTmaxRcvTime 5 nviHotWaterHeartBeat

Discharge Temperature

nviDischAirTemp SCPTmaxRcvTime 6 nviDischAirTempHeartBeat

Fan Speed Command

nviFanSpeedCmd SCPTmaxRcvTime 7 nviFanSpeedCmdHeartBeat

Energy Hold Off nviEnergyHoldOff SCPTmaxRcvTime 8 nviEnergyHoldOffHeartBeat

Shedding Command

nviShedding SCPTmaxRcvTime 9 nviSheddingHeartBeat

Slave Input nviSlave SCPTmaxRcvTime 10 nviSlaveHeartBeat

Outdoor Temperature

nviOutdoorTemp SCPTmaxRcvTime 11 nviOutdoorTempHeartBeat

Hardware Output Valve

nviExtCmdOutput(x) SCPTmaxRcvTime 12–18

nviExtCmdOutputxHeartBeat

Table 13: Disconnect AlarmsSensor Time

Disconnected Bit # Programmatic Name

Space Temperature Sensor

30 seconds 25 SpaceTempSensorFault

Discharge Air Temperature Sensor

30 seconds 26 DischargeTempSensorFault

Water Temperature Sensor

30 seconds 27 WaterTempSensorFault

Setpoint Offset 30 seconds 28 SetpointOffsetElecFault


These settings can be entered on the Alarm dialog box of the Fan Coil Unit Controller Configuration Wizard (Figure 25). Table 14 describes the configuration variables for user-set alarms.

Setting up the Fan Coil ControllerThis section gives you step-by-step instructions for setting up the Fan Coil Unit Controller using the configuration wizard. The definition of the terms used in the configuration wizard and a short explanation of how to use each section of the configuration wizard are provided.

Each window of the configuration wizard is discussed under its own heading (for example, Heating-Cooling Configuration) and introduced by a large graphic of that window.

The following information is in the same order as it appears in the Fan Coil Unit Controller Configuration Wizard.

Persistent Network VariablesNote: Read this section about how to make network variables persistent. This

information could save you a great deal of time.

When the network variable is marked as persistent, the network variable value is written to Electronically Erasable Programmable Read-Only Memory (EEPROM). Once written to EEPROM, the network variable value is preserved through power outages and resets. Every time it receives a new network variable value, the new value is written into EEPROM.

However, EEPROM only accepts a limited number of data writes. The number of writes that EEPROM accepts is great, but it is still limited. If the network variable input is constantly changing, the network variable could exhaust the ability of the EEPROM to store it in permanent memory.

If the value of the network variable is constant, and if it is received on the network input at a fixed time interval, this does not cause the EEPROM to write new data. The EEPROM only writes new data when the data value changes.

For these reasons, network variables that change infrequently (for example, nviSetPoint network variables) are better candidates for persistence than others.

Table 14: Configuration Variables for User-Set AlarmsMonitored Point

Alarm Type

Setpoints Bit#

Programmatic Name

Location Setpoints/ Delta

Time DelayLocation

Space Temperature

Deviation active heatingsetpoint - offset

29 LowSpaceTemp UCPTspaceTempAlarmOffset

UCPTspaceTempAlarmTime

active coolingsetpoint + offset

30 HighSpaceTemp

Discharge Air Temperature

Low low limit setpoint 31 LowDischargeTemp UCPTsupplyTempLoLimit

UCPTsupplyTempAlarmTime

High high limit setpoint 32 HighDischargeTemp UCPTsupplyTempHiLimit


Setting UnitsMeasurement units are shown at the bottom of the Fan Coil Unit Controller Configuration Wizard menu. Select measurement units before you perform any other tasks. When you change the measurement units, all unsaved information you have entered into Fan Coil Unit Controller Configuration Wizard is lost.

However, if you change your system measurement unit, all the SNVT format types also change. The measurement units you select in the wizard, either SI or Imperial, have an effect on the nvoHwInputx SNVT format type. Once you configure an input through the wizard and select a SNVT Type, the format type is written in the database and a change of the system measurement unit no longer has an effect on that network variable.

Note: If you are using Imperial units of measure (such as degrees Fahrenheit, inches of water, and Btu), see the Units in LONWORKS Networks section.

Input ConfigurationWhen you configure inputs, you set the signal type, signal interpretation, and the SNVT that transmits the information over the network. You can configure inputs through the sensor configuration wizard. The sensor configuration wizard can be launched from either the Fan Coil Unit Controller Configuration Wizard or the Hardware Input LONMARK object in the LX-FCUL wizard view of the device. In the Fan Coil Unit Controller Configuration Wizard, leave the corresponding input UNUSED (Figure 28).


Configuring an Input1. The numbers in the Sensor Input column correspond to the input numbers of

the LX-FCUL. Click the drop-down arrow next to the input number you wish to configure.

2. Select an input type. Table 15 gives a brief description of the possible selections.

Table 15: Sensor Input Usage OptionsInput Selection DescriptionUNUSED Input not used by fan coil

SPACE_TEMP Space temperature input

WATER_TEMP Water temperature input

DISCHARGE_TEMP Discharge temperature input

SETPOINT Setpoint Offset input

OCC_CONTACT Occupancy sensor input

BYPASS_CONTACT Bypass contact input

WINDOW_CONTACT Window open/closed input

FAN_SPEED_SELECTOR Fan speed input

MODE_SELECTOR_HVAC Mode selector input

FAN_STATE Fan state input

Figure 28: Object Inputs Configuration Window


3. Click Configure. The Sensor Configuration dialog box appears.

4. Enter the configuration settings and click OK.

The sensor configuration properties determine the frequency of network variable propagation. Use the Delta Value and Throttle to adjust a node’s overall transmission rate to the available network bandwidth. The transmission rate is particularly important when the network variable value changes frequently; for example, a sensor reading.

Heartbeat (Max Send Time)The maximum time period between automatic transmissions of the network variable on the network (whether the value of the variable has changed or not). Set Heartbeat to 0 to disable Heartbeat.

Heartbeat is also referred to as Maximum Send Time.

Throttle (Min Send Time)Throttle is the minimum time period that must pass between network variable updates on the network. If the value of the network variable changes by more than the configured Delta Value, an update is sent only after this time expires. Set Throttle to 0 to disable Throttle.

Throttle is also referred to as Minimum Send Time.

Delta ValueIndicates the minimum value change required to update the associated network output variable.

Figure 29: Sensor Configuration Dialog Box


Override ValueThe value the network variable adopts when the Sensor object is in the overridden state.

Default ValueThe value the network variable adopts when the Sensor object is in the disabled state, or the sensor reading is invalid.

Sensor Hardware PropertiesThe hardware configuration properties of a particular sensor input. Settings made here correspond to the characteristics of the sensor hardware connected to the input.

Input Signal InterpretationDetermines how the input reading is converted into units of measurement (for example, degrees Celsius). See Table 16.

Signal Interpretation Type selections might be limited if a Heating, Ventilating, and Air Conditioning (HVAC) object (for example, a heat pump object) uses a particular sensor input implemented on the same node.

The configuration property entry fields change depending on the selected Signal Interpretation Type.

Signal TypeDetermines the input signal type of the connected sensor. The following signal types are supported:

RESISTANCE–Resistive of Contact input

VOLTAGE_0_10V–0 to 10 Volt input

MILLIAMPS_4_20MA– 4 to 20 milliamp input

Table 16: Signal Interpretation TypesSignal Interpretation Types DescriptionDISCONNECTED Input not used, default value applies

LINEAR Linear Interpolation

TRANS_TABLE Translation Table

DIGITAL 2-state input (ON/OFF)

MULTI_LEVEL Multi-level input uses signal increment

STD_THERMISTOR Predefined translation table

SETPOINT_OFFSET Linear Interpolation with deadband


Thermistor TypeIf the associated input is a thermistor (THR) type, use this field to select the predefined translation table for linear interpolation of input values. See Table 17.

OffsetThe sensor-specific zero offset in measurement units. This value is added after translation/conversion of the raw signal.

Max Value, Min ValueDepending on the Input Signal Interpretation type, this settings has a different meaning. For LINEAR and SETPOINT_OFFSET types, they determine the range of the sensor in measurement units mapped to the predefined span of the hardware input signal (10 V, 16 mA, and so on). Linear interpolation calculates the sensor value.

For all other non-discrete Input Signal Interpretation Types, these settings define the upper and lower limit of the sensor object’s output value.

ReverseUse this checkbox to reverse the object’s output value. This setting applies to discrete inputs (ON/OFF) only.

IncrementDefines the increase of input signal necessary to increment the output value (for example, network variable) by one, starting from zero.

For example: If the increment setting is 2 V, the network variable value is 3 at 6 V.

TransTableOpens a small window providing a table of 16 signal/value pairs to define a translation table for conversion of raw measured data into units of measurement. Input values are in kilo-ohm, V, or mA, with respect to the Input Signal Type chosen. Output values are in units according to the object’s selected output network variable type. Only values within the sensor range defined by Max Value and Min Value are considered.

Table 17: Thermistor TypesThermistor Type DescriptionDEFAULT_TYPE ACI/10K-CP

TYPE_2 ACI/10K-CP

TYPE_3 ACI/10K-AN

TYPE_7 Greystone 10K, type 7

TYPE_12 Mamac Systems 10K, type 12

TYPE_24 Greystone 10K, type 24


Get ValueThis button is active when the associated device is configured, online, and connected. Once all hardware properties are set appropriately, click this button to retrieve the current sensor value form the network.

Configuring an Input Represented as a LONMARK ObjectTo configure an input represented as a LONMARK object:

1. Select the Hardware Input LONMARK object on the left side of the LX-FCUL Wizard view of the device. Select the Sensor Configuration wizard on the right side of the view. Click Launch.

2. Click the Configure button.

3. In the Sensor Configuration dialog box (Figure 29), make the required selections. See Configuring an Input for details.


Output ConfigurationWhen you configure outputs, you define the function, override value, and signal type. You can configure outputs with the Actuator Wizard and launch it from the Fan Coil Unit Controller Configuration Wizard Object Outputs Configuration window (Figure 30). Table 18 describes all possible outputs that you can select from the Object Outputs Configuration window.

Table 18: Output Selection and Description (Part 1 of 2)Selection Output DescriptionFAN_SPEED_1 Fan control output, speed 1

FAN_SPEED_2 Fan control output, speed 2

FAN_SPEED_3 Fan control output, speed 3

LOCAL_HEATING_1 Heating control output, stage 1



LOCAL_COOLING_1 Cooling and heat pump heating control output, stage 1



REVERSING_VALVE Two state (opened or closed) reversing valve output

HEAT_VALVE_OPEN Heating floating valve output, open command

HEAT_VALVE_CLOSE Heating floating valve output, close command

HEAT_VALVE_ON_OFF Digital heating valve control output

COOL_VALVE_OPEN Cooling floating valve output, open command

COOL_VALVE_CLOSE Cooling floating valve output, close command

COOL_VALVE_ON_OFF Digital cooling valve control output

Figure 30: Fancoil Object Outputs Configuration Window


The Actuator Wizard can be launched from either the Fan Coil Unit Controller Configuration Wizard or from the Hardware Output LONMARK Object in the LX-FCUL Wizard view of the device. Hardware output is used to control any equipment that is not related to the Fan Coil Unit Controller. To do so, configure the output with the actuator wizard launched from the hardware output LONMARK Object. In the Fan Coil Unit Controller Configuration Wizard, leave the corresponding output UNASSIGNED. To control that output, use the nviExtCmdOutputx.

Output Signal TypesThree possible output signals are available. The output signals available for selection depend on the output type you select. A brief description of each type follows:

Digital - A signal that has only two states: ON and OFF.

PWM - A pulsed signal where the time duration of the pulse (called the duty cycle) varies proportionally to the value transmitted. For example, a greater duty cycle is converted as a greater value.

Analog - A signal that is continuous over its entire range from 0 to 10 volts.

Configuring an OutputTo select and configure an output:

1. On the Object Outputs Configuration window, numbers in the column Control Output correspond to the output numbers. Click the drop-down arrow next to the control output number that you want to configure.

2. Select an output type. See Table 18 for a brief description of the possible selections.

3. If you want to assign an override value, select the box labeled Permit Override and then enter an override value as a percentage of the total output value. If you have chosen a digital output such as FAN_SPEED_1, then the override box changes to provide you with the option of ON or OFF for your override.

HEAT_COOL_VALVE_OPEN Heating/cooling floating valve output, open command

HEAT_COOL_VALVE_CLOSE Heating/cooling floating valve output, close command

HEAT_COOL_VALVE_ON_OFF Digital heating/cooling valve control output

FAN_SPEED_MOD Fan control output, variable speed

LOCAL_HEATING_MOD Modulated heating control output

HEATING_VALVE_MOD Modulated heating valve output

COOLING_VALVE_MOD Modulated cooling valve output

HEAT_COOL_VALVE_MOD Modulated heating/cooling valve output

Table 18: Output Selection and Description (Part 2 of 2)Selection Output Description


Note: Outputs are overridden by use of the Fan Coil Unit Controller LONMARK Object command. This command is available from the Object Manage window of the Fan Coil Unit Controller Configuration Wizard. Click Override ON to enable the override, and Override OFF to disable it.

4. Select the Local Hardware box if the output is connected to a physical actuator, such as a motor or valve.

5. Click Configure.

6. In the Actuator Configuration dialog box (Figure 31), click the drop-down arrow and select the output signal appropriate for your application. The output signal selection presented to you depends on the choice you made in Step 2. See the Output Signal Types section for more information.

Note: Reverse Output - Normally, an output is ON when the output components are supplying 100% of the rated voltage. If you want the output to supply 0% of the rated voltage when ON, select the Reverse box. For a digital output, the output is normally ON when the contacts are closed. When you reverse a digital output, the output is ON when the contacts are open.

You have now configured an output.

Figure 31: Actuator Configuration Dialog Box


Configuring an Output Represented as a LONMARK ObjectTo configure an output represented as a LONMARK Object:

1. Select the Hardware Output LONMARK Object on the left side of the LX-FCUL Wizard view. Select the Actuator Configuraton on the right side of the view. Click Launch and select Configure. The Hardware Output Configuration window displays (Figure 32).

2. In the Output Type box, select the type of output signal. See the Output Signal Types section for more information.

Note: Reverse Output - Normally, an output is ON when the output components are supplying 100% of the rated current and voltage. For a digital output, the ON state occurs when the contacts are closed. If you want the output when ON to supply 0% of the rated current and voltage or for the digital contacts to be open, then select the Reverse box.

3. Enter an override value as a percentage of the total output to assign an override value.

Note: Normally, digital outputs are closed at 100% and open at 0%. See the preceding Reverse Output note. Outputs are overridden by use of the actuator LONMARK Object command. This command is available from the Object Manage window of the actuator wizard.

4. Enter a default value in the Default Value box.

The default values are used when the Fan Coil Unit Controller is in the default state. The Fan Coil Unit Controller may enter the default state at startup. The state that the Fan Coil Unit Controller enters at startup is selected during commissioning.

Figure 32: LX Actuator Configuration,Hardware Output Configuration Window


Heating-Cooling ConfigurationOn the Heating-Cooling configuration window, you define:

• occupied, standby, and unoccupied setpoints in both heating and cooling mode

• maximum and minimum discharge temperatures

• bypass time and change over delay (See A in Figure 33.)

• Optimum Start settings (See B in Figure 33.)

• Cooling stage minimum time On and Off (See C in Figure 33.)

Optimum StartOptimum Start prepares the space for occupancy in advance of the occupied period. The Fan Coil Unit Controller uses stored daily statistics to calculate the length of time required each day to reach the occupied setpoints just as actual occupancy begins.

See the main Optimum Start section for more information.

Note: For Optimum Start to work, the network variable nviOccCmd must be set to SNVT type SNVT_tod_event Set the SNVT type using the Changeable Nv Manager view of the device in FX Workbench. See Change Network Variable Type for details.

Figure 33: Heating-Cooling Configuration Window

C

AB


Table 19: Heating-Cooling Configuration ParametersField DescriptionHeatingOccupied/Bypass Displays the heating setpoint for the occupied and bypass states.

Standby Displays the heating setpoint for the standby state.

Unoccupied Displays the heating setpoint for the unoccupied state.

Maximum DischargeTemperature

Displays the highest discharge air temperature you allow during the heating state.

Minimum HeatingTime

Displays the length of time that the duct and perimeter heating must stay ON once it has turned ON, and the length of time that the heating must stay OFF once it has turned OFF. Minimum heating time affects duct heating, perimeter heating, and staged outputs. Once a staged output has changed state, the next staged output cannot change state until the minimum heating time has passed.Note: Minimum Heating Time does not apply to modulated heating.

CoolingOccupied/Bypass Displays the cooling setpoint for the occupied and bypass states.

Standby Displays the cooling setpoint for the standby state.

Unoccupied Displays the cooling setpoint for the unoccupied state.

Minimum DischargeTemperature

Displays the minimum temperature of the discharge air that you allow during the cooling state.

Minimum Time ON Displays the minimum ON time for both heating and mechanical cooling.

Minimum Time OFF Displays the minimum OFF time for mechanical heating and cooling.

Optimum StartMaximum Start Time Set the maximum length of time before the start of occupancy mode that

the Fan Coil Unit Controller starts to heat or cool the space.

Enable Optimum Start for Heating

Allows the Fan Coil Unit Controller to cool the space so that the space temperature is within the occupied setpoints when the occupied period begins.

Enable Optimum Start for Cooling

Allows the Fan Coil Unit Controller to cool the space so that the space temperature is within the occupied setpoints when the occupied period begins.

Use Maximum Time If No Statistics

Allows the Fan Coil Unit Controller to use the maximum start time as the length of time needed to heat or cool the space before occupancy. Once Optimum Start statistics have been recorded, Fan Coil Unit Controller uses Optimum Start time periods calculated from the statistics. The maximum start time can only be used to limit the length of the Optimum Start time.If this option is not selected, the Fan Coil Unit Controller begins to heat or cool the space at the beginning of the occupied period. After the first start, it heats or cools the space at the recorded Optimum Start time. After the second start, it heats or cools the space at the calculated Optimum Start time.

GeneralHeat/Cool Change Over

Displays the time interval that must pass before heating can occur after cooling or cooling can occur after heating.

Bypass Time Displays the bypass time. Bypass time is the duration of bypass mode that begins when the bypass button is pressed in unoccupied or standby mode. Remember that bypass time does not limit a bypass period commanded by nviOccCmd.

Enable Frost Protection

Allows the heat to turn ON at a space temperature of 43°F (6°C) and turned off at 46°F (8°C). The heat can turn ON regardless of the temperature control. For example, the heat can turn ON when nviApplicMode is set to HVAC_OFF. The heating order determines the time in which the heat turns on.


Fan-Valve ConfigurationOn this window, you select the type of fan input, fan operation, and floating valve operating properties (Figure 34).

Table 20: Fan-Valve Configuration ParametersField DescriptionFan Speed Allows your sensor to measure the fan speed.

Fan Current Allows your sensor to measure the current drawn by the fan.

Current Threshold Sets the current at which you consider the fan to be ON. This affects the alarm that compares the states of the fan input and fan output.

Minimum Speed Displays the fan minimum speed.

ON/OFF Period Displays the period of time that must pass before the fan can turn ON after turning OFF; or the fan can turn OFF after turning ON.

Always ON in Occupied Mode Forces the fan to run continuously during occupied mode. If this option is not selected, the fan runs only when there is a heating or cooling demand.

Minimum ON/OFF Period Displays the period of time that must pass before the fan can turn ON after turning OFF, or the fan can turn OFF after turning ON.

Minimum Position Displays the valves minimum position when there is a heating or cooling demand. The valves are fully closed when heating or cooling demand ceases.

Drive Time for Floating Valves Displays the period of time required for the valve to move from the fully closed to the fully open position.

Figure 34: Fan-Valve Configuration Window


PID ConfigurationThe Fan Coil Unit Controller uses PID Loops to control the space temperature and the discharge temperature.

Table 21: PID Configuration ParametersField DescriptionProportional Gain Displays the gain per unit of the error.

Integral Gain Displays the gain per unit of the error.

Integral Time Displays the error repetitively sampled, and the integral gain is added to the output. The period of time between samples is the integral time. Enter the integral time for your process.

Derivative Gain Displays the derivative time–the time between two samples of the error. The two samples are compared to find the change in the error.

Deadband Displays a number to define the size of the deadband. The deadband is a range of values symmetrical about the setpoint. See the Deadband section for more information.

Use Discharge Air Temperature Only for Limitation

Allows the Fan Coil Unit Controller to control the unit with the room demand, and limits the discharge temperature between the minimum and maximum discharge temperature.If this option is unchecked, the Fan Coil Unit Controller tries to maintain the calculated discharge temperature setpoint. The discharge setpoint is calculated with a linear equation between the minimum and maximum discharge air temperature and the space PID loops.

Figure 35: PID Configuration Window


Alarm ConfigurationOn this window, you can set the alarm high and low limits, offset, and alarm delays (Figure 36).

Alarms monitor network variables or control points. These variables or points are called monitored variables. When a monitored variable has a value that causes an alarm message to be transmitted, the monitored variable is in the alarm state.

Table 22 describes the alarm configuration parameters.

Space TemperatureSpace Temperature alarm has an alarm delay and an alarm offset. In this case, the alarm becomes active when both of the following events occur:

• The monitored temperature is outside of the range bounded by the setpoint ± alarm offset.

• This preceding condition exists for a length of time greater than the alarm delay.

Table 22: Alarm Configuration ParametersField DescriptionAlarm Delay Enter the length of time that an input must be in the alarm state before an alarm

sounds.

Alarm Offset Enter the amount of deviation from the setpoint that causes an alarm to sound.

Alarm Low Limit

Enter a value less than the value in which the alarm becomes active. The alarm becomes active when the monitored variable falls below this value.

Alarm High Limit

Enter a value greater than the value in which the alarm becomes active. The alarm becomes active when the monitored variable rises above this value.

Figure 36: Alarm Configuration Window


Discharge TemperatureThis alarm has an alarm delay and high and low limit. In this case, the alarm becomes active when both of the following events occur:

• The monitored temperature is outside of the range marked by the high and low limits.

• This preceding condition exists for a length of time greater than the alarm delay.

Fan AlarmThe Fan alarm applies to the fan state only. The fan alarm becomes active when one of following conditions exists for a time period greater than the alarm delay:

• The fan command is ON, and the fan input differs from the fan output, or the fan current is lower than the fan current threshold.

• The fan command is OFF, and the fan input differs from the fan output, or the fan current is higher than the fan current threshold.

The Fan Alarm monitors the fan speed or fan current in both the ON and OFF fan states. The alarm delay must be long enough to allow the fan to reach the ON or OFF stage. The fan speed or fan current level is set in the Fan-Valve Configuration window.

Similarly, a variable speed fan requires time to speed up or slow down so that its speed matches the output. The alarm delay must be long enough to allow the fan to reach its commanded speed; otherwise, false alarms occur.


Network Input ConfigurationFigure 37 shows the Network Input configuration window. Table 23 describes the parameters.

Heartbeat AlarmsAn alarm occurs if the period between received values of these variables exceeds the value you enter into the Heartbeat column. For more information, see the Alarm Operation section.

Table 23: Network Input ParametersField DescriptionHeartbeat Sets the maximum time between updates for the associated network input.

When the heartbeat interval has passed without an update, the network input enters the heartbeat failure state, and its value becomes invalid.

Persistent Allows the network variable to remain in memory after a power failure and/or reset. Do not make frequently changing network variables persistent.

Figure 37: Network Input Configuration Window


Network Output ConfigurationThe Network Output window enables you to control network traffic to reduce network congestion, but transmits data as quickly as is necessary for your application.

The Network Outputs window enables you to control the frequency of network variable transmissions through several different parameters. On the Network Outputs Configuration window, you can configure:

• heartbeat period for network outputs

• Send on Delta quantity

• throttle settings for several network outputs

You can also set the maximum and minimum send times for all other network variables (Figure 38).

Table 24: Network Output Configuration ParametersField DescriptionHeartbeat The maximum time period between transmissions of the network

variable.

Send on Delta Enter the amount of change of the value of the network variable that must occur before the variable is transmitted. The network variable is transmitted whenever this amount of change occurs.

Throttle Enter the minimum time period that must pass before a network variable is transmitted.

General The values entered in the General box affect all other network variables not listed here.

Maximum Send Time Enter the maximum time between transmissions of network variables.

Minimum Send Time Enter the minimum time between transmissions of network variables.

Figure 38: Network Output Configuration Window


Object ManageTo use the Object Manage window, you must configure the Fan Coil Unit Controller and have it online and in communication with the FX Supervisory controller (Figure 39). Table 25 describes the Object Manage parameters.

Table 25: Object Manage ParametersField DescriptionDevice State Displays the current state of the LONMARK object.

Object Status Displays only the red active status flags when selected.The Object Status area is empty when the Fan Coil Unit Controller is in its normal state.

Get Status Refreshes status information for devices in the Object Status pane.

Clears Status Clears all status flags and removes all messages. Clicking Get Status retrieves new information. This is used to check if a problem condition is solved.

Override ON Places the Fan Coil Unit Controller into the override state. Control outputs including the network variables and linked hardware outputs are set to their configured override value or state.

Override OFF Ends controller override.

Enable Enables the controller after an override.

Disable Sets the LONMARK object to the disabled mode. In the disabled mode, control outputs are at their configured disabled state.

Request Allows advanced users to query the LONMARK using the LONMARK object and commands.To query the LONMARK object:Select a command from the drop-down list beside the request button.Click the Request button.

Figure 39: Object Manage Window


Object StatusThe Object Status messages are listed here with references to tables describing the causes.

Communication Failure This message results from a heartbeat failure on a network variable input that sets the comm_failure bit of nvoStatus. See Table 12.

Electrical Fault

This message indicates that a local hardware sensor is disconnected. The disconnect condition sets the electrical_fault bit of nvoStatus. See Table 13 for a list of the possible disconnected sensors.

Out of Limits

This message indicates that a monitored point has exceeded limits set by the operator who configured the device. The out-of-limits sets the out_of_limits bit of nvoStatus. See Table 14.

Disabled

Active when the device is disabled (press the Disable button).

Table 26: Values for SNVT_obj_request1Value Identifier Meaning0 RQ_NORMAL Enable object and remove override.

1 RQ_DISABLED Disable object.

2 RQ_UPDATE_STATUS Report object status.

3 RQ_SELF_TEST Perform object self test.

4 RQ_UPDATE_ALARM Update alarm status.

5 RQ_REPORT_MASK Report status bit mask.

6 RQ_OVERRIDE Override object.

7 RQ_ENABLE Enable object.

8 RQ_RMV_OVERRIDE Remove object override.

9 RQ_CLEAR_STATUS Clear object status.

10 RQ_CLEAR_ALARM Clear object alarm.

11 RQ_ALARM_NOTIFY_ENABLED Enable alarm notification.

12 RQ_ALARM_NOTIFY_DISABLED Disable alarm notification.

13 RQ_MANUAL_CTRL Enable object for manual control.

14 RQ_REMOTE_CTRL Enable object for remote control.

15 RQ_PROGRAM Enable programming of special configuration properties.

16 RQ_CLEAR_RESET Clear the RESET_COMPLETE flag.

17 RQ_RESET Execute a reset sequence, set the RESET_COMPLETE flag when done.

1. Not all commands are available in the Fan Coil Unit Controller.


In AlarmActive if a communications failure or electrical fault has occurred, or if any of the conditions in the Alarm Configuration window are met.

In Override

Active when the device is in override (press the Override button).

Out of ServiceActive when the FCU controller cannot control the temperature in the zone of control because it is not receiving a space temperature, or there is no slave input (nviSlave).


Network VariablesThe following text describes some of the most commonly used network variables found in the Fan Coil Unit Controller.

nviApplicModeYou can use this network variable input to coordinate the Fan Coil Unit Controller with the following devices:

• air handler controller

• any other supervisory controller

• HMI

Type: SNVT_hvac_mode (108)

nviDischargeTempTransmits discharge temperature from a network device to the FCU Controller. Network values have priority over local sensor values.

Type: SNVT_temp_p (105)

Table 27: nviApplicModeValue Identifier Notes0 HVAC_AUTO Controller automatically changes between application

modes.

1 HVAC_HEAT Heating only.

2 HVAC_MRNG_WRMUP Application-specific morning warm-up.

3 HVAC_COOL Cooling only.

4 HVAC_NIGHT_PURGE Application-specific night purge.

5 HVAC_PRE_COOL Application-specific pre-cool.1

1. Not supported in the Fan Coil Unit Controller.

6 HVAC_OFF Controller not controlling outputs.

7 HVAC_TEST Equipment being tested.1

8 HVAC_EMERG_HEAT Emergency heat mode.1

9 HVAC_FAN_ONLY Air not conditioned, fan turned on.

10 HVAC_FREE_COOL Cooling with compressor not running.1

11 HVAC_ICE Ice-making mode.1

0xFF HVAC_NUL Value not available.


nviEnergyHoldOffThis network variable input receives the energy hold-off demand. Like Window Contact, this command sets the occupancy schedule to unoccupied. See the Window Contact Input section for more information.

When state and value are not set to zero, the energy hold-off is ON. When state or value is set to zero, the energy hold-off is OFF.

Type: SNVT_switch (95)

nviExtCmdOutputxThese are numbered following the output number. For example, nvoExtCmdOutput1, nvoExtCmdOutput2, and so on. These network variable inputs receive the output signal, whether state or percentage, to control any output that is unassigned and configured through the actuator configuration wizard.


nviFanSpeedCmdThis network variable input receives the fan speed demand. It receives a value between 0–100%, and a state 0–1. If, for example, you have 3 fan speeds, fan speed 1 starts over 33%, fan speed 2 starts over 66%, and fan speed 3 starts over 100%. To start, the field state must be ON (1).


nviHotWaterThis network variable input receives the water state. Water state refers to whether the water is hot or cold.

When state and value are not set to zero, the water state is hot. When state or value is set to zero, the water state is cold.


nviOccCmd and nviOccManCmdThis network variable input is used to command the Fan Coil Unit Controller object into different occupancy modes. See the Mode Selection section for more information. Table 28 shows the nviOccCmd and nviOccManCmd values.

Type: SNVT_occupancy (109), or SNVT_tod_event (128)Table 28: Values of nviOccCmd and ModesValue Identifier Fan Coil Unit Controller Mode0 OC_OCCUPIED Occupied Mode

1 OC_UNOCCUPIED Unoccupied mode

2 OC_BYPASS Bypass mode

3 OC_STANDBY Standby mode

0xFF OC_NUL Invalid data


nviOutdoorTempThis network variable input receives the outdoor air temperature.


nviSetPointUse this network variable input to change the temperature setpoints for the occupied and standby modes via the network. The individual heating and cooling setpoints for the occupied and standby modes are calculated from nviSetPoint.


nviSetPtOffsetUse this network variable input to shift the temperature setpoint by adding the value of nviSetPtOffset to the current setpoint. This network variable operates on occupied and standby setpoints only, and does not affect the unoccupied setpoint.


nviSheddingUse this network variable input to reduce the Fan Coil Unit Controller power consumption. For example, if nviShedding is set to 25%, then heating and cooling do not exceed 75%.

Type: SNVT_lev_percent (81)

nviSlaveUse this network variable input to force the Fan Coil Unit Controller to follow the demands of another fan coil unit controller. It is normally bound to the nvoUnitStatus of the other controller.

Type: SNVT_hvac_status (112)

nviSpaceTempTransmits space temperature from a network device to the Fan Coil Unit Controller. Network values have priority over local sensor values.


nviWaterTempTransmits water temperature from a network device to the Fan Coil Unit Controller. Network values have priority over local sensor values. If both nviHotWater and nviWaterTemp are received from the network, nviHotWater has priority over the nviWaterTemp.



nvoCoolOutputThis network variable output sends the cooling demand of the controller in percentage.


nvoCtrlOutputxThese are numbered following the output number. For example, nvoCtrlOutput1, nvoCtrlOutput2, and so on. These network variable outputs send the output signal, whether state or percentage, to any actuators.


nvoEffectSetPtThis network variable output sends the effective setpoint in use by the fan coil object.


nvoFanSpeedThis network variable output sends the fan speed.


nvoFCalarmTable 29 describes the nvoFCalarm parameters.

Type: SNVT_state_64 (165)

Format: UNVT_fc_alarmTable 29: nvoFCalarm (Part 1 of 2)Programmatic Name Bit

NumberMeaning When Bit Is Set

nviSpaceTempHeartBeat 0 Heartbeat failure reported from nviSpaceTemp.

nviApplicModeHeartBeat 1 Heartbeat failure has occurred in nviApplicMode.

nviSetPtOffsetHeartBeat 2 Heartbeat failure has occurred in nviSetPtOffset.nviOccCmdHeartBeat 3 Heartbeat failure has occurred in nviOccCmd.

nviWaterTempHeartBeat 4 Heartbeat failure has occurred in nviWaterTemp.

nviHotWaterHeartBeat 5 Heartbeat failure has occurred in nviHotWater–This network variable input transmits the water state: hot or cold.

nviDischTempHeartBeat 6 Heartbeat failure has occurred in nviDischAirTemp.

nviFanSpeedCmdHeartBeat 7 Heartbeat failure has occurred in nviFanSpeedCmdState.

nviEnergyHoldOffHeartBeat 8 Heartbeat failure has occurred in nviEnergyHoldOff.

nviSheddingHeartBeat 9 Heartbeat failure has occurred in nviShedding.

nviSlaveHeartBeat 10 Heartbeat failure has occurred in nviSlave.


nvoFCstateThis network variable output sends the fan coil status. It provides the configuration errors and mode status.

Type: SNVT_state_64 (165)

Format: UNVT_fc_state

nviOutdoorTempHeartBeat 11 Heartbeat failure has occurred in nviOutdoorTemp.

nviExtCmdOutputxHeartBeat 12-18 Heartbeat failure has occurred in nviExtCmdOutput.

SpaceTempSensorFault 24 Space temperature sensor disconnected for more than 30 seconds.

DischargeTempSensorFault 25 Discharge temperature sensor is disconnected for more than 30 seconds.

WaterTempSensorFault 26 Water temperature sensor is disconnected for more than 30 seconds.

SetpointOffsetElecFault 27 Setpoint offset is disconnected for more than 30 seconds.

LowSpaceTemp 28 Space temperature is lower than the active heating setpoint by more than the offset for a period of time greater than the alarm delay.

HighSpaceTemp 29 Space temperature is higher than the active heating setpoint by more than the offset for a period of time greater than the alarm delay.

LowDischargeTemp 30 The discharge temperature is lower than the low limits setpoint for a time greater than the time defined in the alarm delay.

High DischargeTemp 31 The discharge temperature is higher than the high limits setpoint for a time greater than the time defined in the alarm delay.

Table 30: nvoFCstate (Part 1 of 2)Programmatic Name Bit


OutOfService 0 The device is out of service. There is no space temperature sensor configured or nviSlave is not bound.

FanInManualCtrl 1 The fan speeds are controlled by the fan speed selector input or the nviFanSpeedCmd.

HotWater 2 The water is hot.

CtrlOutputxOverridden 8-14 The fan coil object output is overridden

HwOutputxOverridden 15-21 The hardware output is overridden.

DupWaterTempCfgError 48 Duplicate water temperature sensor configuration error.

DupDischTempCfgError 49 Duplicate discharge air temperature sensor configuration error.

DupOccContactCfgError 50 Duplicate occupancy contact sensor configuration error.

Table 29: nvoFCalarm (Part 2 of 2)Programmatic Name Bit



nvoHeatOutputThis network variable output sends the heating demand of the fan coil in percentage.


nvoHwInputxThese are numbered following the input number (for example, nvoHwInput1, nvoHwInput2, and so on). These network variable outputs send the input value over the network with their own changeable SNVT type.

Type: Changeable type

nvoOccStateThis network variable output sends the occupancy state used by the fan coil object.

Type: SNVT_occupancy (109)

nvoSpaceTempThis network variable output sends the space temperature used by the fan coil object.


DupBypassCntctCfgError 51 Duplicate bypass contact sensor configuration error.

DupWindowCntctCfgError 52 Duplicate window contact sensor configuration error.

DupFanSpeedSelCfgError 53 Duplicate fan speed selector sensor configuration error.

DupModeSelCfgErrors 54 Duplicate mode selector sensor configuration error.

NoFanOutputCfgError 55 No fan output configuration error.

NoHeatOrCoolCfgError 56 No heat or cooling output configuration error.

FanSpeedOutCfgError 57 Fan speeds or modulation configuration error.

HeatValveCfgError 58 Heating valve configuration error.

CoolValveCfgError 59 Cooling valve configuration error.

HeatCoolValveCfgError 60 Heating and cooling valve configuration error.

HeatStagesCfgError 61 Heating stages configuration error.

CoolStagesCfgError 62 Cooling stages configuration error.

RevValvWOCoolCfgError 63 Reversing Valve without cooling stages configuration error.

Table 30: nvoFCstate (Part 2 of 2)Programmatic Name Bit



nvoTerminalLoadThis network variable output sends the energy demand of the fan coil in percentage. Positive values are cooling demand, and negative values are heating demand.


nvoUnitStatusThis network variable output sends the following simultaneously:

• operating mode

• primary heating state as a percentage

• secondary heating state (if relevant) as a percentage

• cooling state as a percentage

• fan state as a percentage

• fan coil alarm state

Type: SNVT_hvac_status (112)

nvoWaterTempThis network variable output sends the water temperature used by the fan coil object.



Standard Network Variable Types (SNVTs)The following are some of the SNVTs more commonly used in the Fan Coil Unit Controller Configuration Wizard.

Change Network Variable TypeChange the network variable type using the FX Workbench software (Figure 40).

Follow these steps to change a network variable type:

1. In FX Workbench LON Device Manager, select the LxFcuL device.

2. Right-click the LxFcuL device and select Views > Changeable Nv Manager.

3. Select the nvName you want to change and click Edit (at the bottom of the window). The Edit Nv Type drop-down menu displays.

4. From the Edit Nv Type drop-down menu select the new SNVT type and click OK.

Note: If the SNVT type you selected requires more memory then allocated by the device for that network variable, the change is not made.

Figure 40: Changeable Nv Manager View

Figure 41: Edit Nv Type Drop-Down Menu


SNVT_hvac_mode (108)Use for heating, ventilating, and air conditioning applications.

SNVT_hvac_status (112) Use for heating, ventilating, and air conditioning applications.

Table 31: SNVT_hvac_modeSNVT_hvac_mode DescriptionSNVT Index 108

Measurement hvac_t

Field Type Category Enumeration

Type Size 1 byte

Valid Type Range hvac_t

Type Resolution 1

Units N/A

Invalid Value HVAC_NUL

Raw Range hvac_t

Scale Factor N/A

File Name SNVT_HV.H

Default Value N/A

Table 32: SNVT_hvac_statusSNVT_hvac_status DescriptionSNVT Index 112

Measurement HVAC Status

Field Type Category Structure

Type Size 12 bytes

Table 33: SNVT_hvac_status StructureField Measurementmode hvac_t

heat_output_primary signed long

heat_output_secondary signed long

cool_output signed long

econ_output signed long

fan_output signed long

in_alarm unsigned short

Table 34: HVAC Status ModeHVAC Status Mode DescriptionField mode

Measurement hvac_t


Type Size 1 byte

Valid Type Range hvac_t

Type Resolution 1


Units N/A

Invalid Value HV_NUL

Raw Range hvac_t

Scale Factor N/A

File Name SNVT_HV.H

Default Value N/A

Table 35: Primary Heat OutputPrimary Heat Output DescriptionField Heat_primary_output

Measurement Primary Heat Output

Field Type Category Signed Long

Type Size 2 bytes

Valid Type Range -163.840–163.830

Type Resolution 0.005

Units Percent of full scale

Invalid Value 32,767 (0x7FFF)

Raw Range -32,768–32,766(0 x 8000–0 x 7FFE)

Scale Factor 5, -3, 0S = a*10b*(R+c)

File Name N/A

Default Value N/A

Table 36: Secondary Heat OutputSecondary Heat Output DescriptionField heat_output secondary

Measurement Secondary Heat Output


Type Size 2 bytes





Raw Range -32,768–32,766


File Name N/A

Default Value N/A

Table 34: HVAC Status ModeHVAC Status Mode Description


Table 37: Primary Cooling OutputPrimary Cooling Output DescriptionField cooling_output

Measurement Cooling Output


Type Size 2 bytes





Raw Range -32,768–32,766(0 x 8000–0 x 7FFE)


File Name N/A

Default Value N/A

Table 38: Economizer OutputEconomizer Output DescriptionField econ_output

Measurement Economizer Output


Type Size 2 bytes





Raw Range -32,768–32,766(0 x 8000–0 x 7FFE)


File Name N/A

Default Value N/A

Table 39: Fan OutputFan Output DescriptionField fan_output

Measurement Fan Output


Type Size 2 bytes





Alarm StateZero (0) means that the unit is not in an alarm state. 255 (0xFF) means that alarming is disabled. All other values (between 1 and 254, inclusive) mean that the unit is in the alarm state. The specific numbers (between 1 and 254) are manufacturer specific as to their meaning, but all represent an alarm state.

SNVT_lev_percent (81)


Raw Range -32,768–32,766(0 x 8000–0 x 7FFE)


File Name N/A

Default Value N/A

Table 40: Alarm State SNVT_occupancy DescriptionField month

Measurement In Alarm State

Field Type Category Unsigned Short

Type Size 1 byte





Raw Range -32,768–32,766(0 x 8000–0 x 7FFE)


File Name N/A

Default Value N/A

Table 41: SNVT_lev_percentSNVT_lev_percent DescriptionSNVT Index 81

Measurement Percentage Level


Type Size 3 bytes



Units Percent of full scale, or parts per million (ppm)

Table 39: Fan OutputFan Output Description


SNVT_occupancy (109)

SNVT_switch (95)

Switch Definition

A structure reporting a percentage level or load value and a discrete on/off state. Separate fields report the percentage value and state. You can use this type for both discrete (on/off) and analog control.

You can use the value field to control the load’s value (for example, position, speed, or intensity). Use the state field to control whether the load is on or off (enabled or disabled). When you use the state field as the output of a discrete sensor device, the OFF state is represented by a SNVT_switch network variable with state = FALSE and value = 0.


Raw Range -32,768–32,766(0 x 8000–0 x 7FFE)


File Name N/A

Default Value N/A

Table 42: SNVT_occupancySNVT_occupancy DescriptionSNVT Index 109

Measurement occup_t


Type Size 1 byte

Valid Type Range occup_t

Type Resolution 1

Units N/A

Invalid Value OC_NUL

Raw Range occup_t

Scale Factor N/A

File Name SNVT_OC.H

Default Value N/A

Table 43: SNVT_switchSNVT_switch DescriptionSNVT Index 95

Measurement Switch


Type Size 2 bytes

Table 41: SNVT_lev_percentSNVT_lev_percent Description


The other discrete states are represented by state = TRUE and value > 0. When used as the output of a two-state sensor device, the ON state is represented by state = TRUE and value = 200 (meaning 100%). When you use as the input of a two-state discrete actuator, a SNVT_switch network variable with state = TRUE are interpreted as the ON state if value > 0, and as the OFF state if value = 0. In addition, a SNVT_switch input network variable with state = FALSE should be interpreted as the OFF state, whether or not value = 0. A state value of 0xFF indicates the switch value is undefined. Table 44: SNVT_switch Input Network VariableValue (raw) State Two-State InterpretationAny 0 Off (0; 0)

0 1 Off (0; 1)

> 0 1 On (200; 1) 1

Any -1 (0 x FF) Invalid (no action)

Table 45: SNVT_switch Output Network VariableValue (raw) State Two-State Interpretation0 0 Off

200 (0xC8) 1 On

0–200(0 x C8) (any valid value)

-1 Invalid (NULL)

Table 46: SNVT_switch Value SNVT_switch Value DescriptionField Value

Measurement State


Type Size 1 byte

Valid Type Range 0–100

Type Resolution 0.5


Invalid Value N/A

Raw Range 0–100(0–0xC8)


File Name N/A

Default Value N/A

Table 47: SNVT_switch State (Part 1 of 2)SNVT_switch State DescriptionField State

Measurement State


Type Size 1 byte

Valid Type Range 0–100


SNVT_temp_p (105)

SNVT_tod_event (128)

Type Resolution 0.5


Invalid Value N/A

Raw Range 0–200(0–0xC8)


File Name N/A

Default Value N/A

Table 48: SNVT_temp_pSNVT_temp_p DescriptionSNVT Index 105

Measurement Temperature


Type Size 2 bytes



Units Degrees Celsius

Invalid Value 32,767(0x7FFF)

Raw Range -27,317–32,767(0x8000–0x7FFE)

Scale Factor 1, 2, 0S = a*10b*(R+c)

File Name N/A

Default Value N/A

Table 49: Occupancy Scheduling EventOccupancy Scheduling Event DescriptionSNVT Index 128

Measurement Time of day event


Type Size 4 bytes

Table 50: SNVT_tod_event: Current StateSNVT_tod_event: Current State DescriptionSNVT Index Current_state

Measurement occup_t


Type Size 1 byte


Table 47: SNVT_switch State (Part 2 of 2)SNVT_switch State Description


Type Resolution 1

Units N/A


Raw Range Occup_t

Scale Factor N/A

File Name SNVT_OC.H

Default Value N/A

Table 51: SNVT_tod_event: Next StateSNVT_tod_event: Next State DescriptionSNVT Index next_state

Measurement occup_t


Type Size 1 byte


Type Resolution 1

Units N/A


Raw Range Occup_t

Scale Factor N/A

File Name SNVT_OC.H

Default Value N/A

Table 52: SNVT_tod_event: Time to Next StateSNVT_tod_event: Time to Next State DescriptionSNVT Index time_to_next_state

Measurement Time to next state

Field Type Category Unassigned long

Type Size 2 bytes

Valid Type Range 0–65,535

Type Resolution 1

Units Minute of hour

Invalid Value N/A

Raw Range 0–65,535(0–0xFFFF

Scale Factor 1, 0, 0S = a*10b*(R+c)

File Name N/A

Default Value N/A

Table 50: SNVT_tod_event: Current StateSNVT_tod_event: Current State Description


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Johnson Controls® is a registered trademarks of Johnson Controls, Inc.All other marks herein are the marks of their respective owners. © 2009 Johnson Controls, Inc.

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LX Series Fan Coil Unit (FCU) Controller User’s Guide

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Transcript of LX Series Fan Coil Unit (FCU) Controller User’s Guide