862 MIR - Instruction Manual Vs30

Instruction manual 862 MIR

Instruction manual 862 MIRMultiple temperature selectorwith MPU, HPU or OPU boardVersion: 3.0Date: February 1997Part no.: 4416.230

Copyright 1996-1997 Enraf B.V. All rights reserved.

Reproduction in any form without the prior consent of Enraf B.V. is not allowed. This manual is for information only. The contents, descriptions and specifications are subject to change without notice. Enraf B.V. accepts no responsibilityfor any errors that may appear in this manual.

The warranty terms and conditions applicable in the country of purchase in respect to Enraf B.V. products are availablefrom the supplier. Please retain them with your proof of purchase.

Enraf B.V.P.O. Box 8122600 AV DelftThe NetherlandsTel.: 015-2698600, Fax: 015-2619574E-mail: 100750.2264 @compuserve.com

Offices in: The Netherlands - China - France - Germany - Singapore - UK - USA

Table of contents

Table of contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.2 Operating principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3 Measuring sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.1 Format critical items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.2 Temperature related settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.3 Additional settings for an 877 FDI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.4 Data items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3 Error codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.1 Temperature error MPU/HPU/OPU (item EM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.2 Temperature status request (item MQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.1 Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.2 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.3 Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.4 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.5 Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.6 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5 Item description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6 Related documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Appendix A ASCII table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Preface


Preface

This manual has been written for technicians involved in the installation, commissioning and service of theEnraf 862 multiple temperature selector unit (MIR) connected to Enraf series 854 level gauges, 877 FDI or873 SmartRadar. For installation of the 862 MIR and the 863 MRT (Multiple Resistance Thermometer), referto the installation guides of these instruments. For an overview refer to the list of related documents inchapter 6.

A description preceding the procedures gives the technical information necessary to understand itsfunctioning. It is recommended to read this description prior to performing any of the procedures.

Safety and prevention of damage

Safe execution of the procedures in this manual requires technical experience in handling tools, andknowledge of safety regulations of electrical installation in hazardous environments.

"Warnings ", "Cautions ", and "Notes " have been used throughout this manual to bring special matters tothe immediate attention of the reader.

• A Warning concerns danger to the safety of the technician or user;• A Caution draws attention to an action which may damage the equipment;• A Note points out a statement deserving more emphasis than the general text, but does not deserve

a "Warning" or a "Caution".

The sequence of steps in a procedure may also be important from the point of view of safety and preventionof damage; it is therefore advised not to change the sequence of procedural steps or alter a procedure.

Legal aspects

The information in this manual is copyright property of Enraf B.V., The Netherlands. Enraf B.V. disclaimsany responsibility for personal injury or damage to equipment caused by:

• Deviation from any of the prescribed procedures;• Execution of activities that are not prescribed;• Negligence of the general safety precautions for handling tools, use of electricity and microwave

radiation.

EC declaration of conformity

This instrument is in conformity with the protection requirements of EC Council Directive 89/336/EEC. The CE conformity marking fulfills the provisions of

EN 50081-2 Generic Emission StandardEN 50082-2 Generic Immunity Standard

when installed, maintained and applied according to requirements as specified in this manual.

Additional information

Please do not hesitate to contact Enraf or its representative if you require additional information.

Introduction

1 Introduction

1.1 General

The 862 MIR temperature selector is used for interfacing an 863 Multiple Resistance Thermometer (MRT).This unit is basically a solid state electronic element selector, containing all hardware necessary forselecting and measuring an MRT with up to 12 temperature elements with one or two spot elements. The862 must always be used in combination with an 854 level gauge, 873 SmartRadar or an 877 Field Displayand Interface. These instruments must be equipped with an MPU, HPU or OPU option board to interface the862 MIR.

1.2 Operating principle

Since most liquids, stored in storage tanks, are not homogeneous in temperature, an average temperaturemeasurement over the entire liquid column is required.A Multiple Resistance Thermometer can provide this true average temperature measurement.An MRT comprises a number of resistance elements of different lengths, all starting near the tank bottom.To measure the average product temperature, the longest fully immersed element is automatically selectedand its temperature measured.

The average gas temperature is calculated by measuring the temperature of the longest resistancethermometer element and subtracting the contribution of the average product temperature. When the MRTis equipped with a spot element in the upper part of the MRT, or there is a separate gas spot element, thenthe gas temperature is measured directly.

The optional board, located in the 854 level gauge, 873 SmartRadar or 877 FDI, selects the longestimmersed element for the average product temperature calculation. The XPU processor in theseinstruments converts the average temperature into a serial Bi-Phase Mark modulated signal which istransmitted via the 2-wire Enraf field bus to the supervisory system.

Intrinsic safety is obtained by applying full galvanic isolation of the primary connections and the remainder ofthe circuitry. The measurement current for the resistance thermometers is 1 mA. Selection of each appropriate resistanceelement is obtained by solid state switches.In order to warrant a maximum integrity and accuracy of the measurement values, a number ofmeasurements is taken, such as:

automatic offset compensationlinearity testinggain calibration

To enable these corrections, a high stable and precise reference and test resistor (0.005% and 3ppm/ °C)are incorporated. All measurements and corrections are performed continuously.All measured data retrieved from the convertor is accompanied by status information and a BCC (BlockCheck Character).

1.3 Measuring sequence

The measuring cycle of the 862 MIR takes approximately 37 seconds. In that time the following data ismeasured (see table on next page).

Introduction


Figure 1.1 Measuring principle

Cycle Measurement

1 Rref

2 ÷ 14 R ÷ R1 13

15 Rgnd

16 Rtest

Each resistance measurement is measured with 1 mA current and without current. The measurementwithout current is an offset measurement.

In measurement cycle 1 a conversion factor is determined: Hz/ohm. With this conversion factor all otherresistance measurements are calculated. This conversion factor is determined with every measurement(37 seconds). In this way an auto calibration of the 862 MIR is obtained.

Commissioning

2 Commissioning

The commissioning of the optional MPU, HPU or OPU board should be performed after the basiccommissioning of the level gauge, radar gauge or indicator. The items mentioned in this section residesunder protection level 2.

2.1 Format critical items

When the temperature dimension and/or the decimal separator has to be changed, it should be done at thestart of the commissioning.

Item Name Description

TD Temperature dimension One ASCII character; either “C” or “F”.• C : degrees Centigrade• F : degrees Fahrenheit

Both dimensions have the same format: sign XXX sep XX.where sign : + or -

X : digit sep : decimal separator (“.” or “,”)

DP Decimal separator One ASCII character; either “.” (point) or “,” (comma).If the instrument is equipped with an XPU 2 board, all relateditems are automatically converted.With an XPU board, all items depending on the temperature,level, density and pressure format have to be re-programmedwith the correct decimal separator.

2.2 Temperature related settings


MT Element type Three ASCII characters (C3 C2 C1). Selects the element typeconnected to the 862 MIR.C3: R refers to an MRT without spot element

Q refers to an MRT with spot elementD refers to an MRT with spot element and

separate gas spot elementE refers to an MRT without spot element and

separate gas spot element

C2 C1: SA Sangamo MRT (-100 ÷ +280 °C)SS Sangamo spot (-100 ÷ +280 °C)BE Beacon MRT (-100 ÷ +280 °C)BS Beacon spot (-100 ÷ +280 °C)PL Pt100 large range (-200 ÷ +250 °C)PS Pt100 small range ( -20 ÷ +120 °C)NI Ni191 ( -20 ÷ +120 °C)CB Cu90 Beacon MRT (-100 ÷ +280 °C)CN Cu90 Nulectron MRT (-100 ÷ +280 °C)CS Cu90 spot (-100 ÷ +280 °C)

For dual spot element configuration, select item MT as DXX orEXX and item MN set to 01 (XX: selection from C2 C1).

Commissioning


Figure 2.1 MRT definitions


MN Number of elements Two ASCII digits. This item specifies the number of elementsfrom the MRT, inclusive the spot element. The maximumnumber of elements is 13.

MR Reference resistor Internal floating point format. For the 862 MIR, the referenceresistance must be set to: +.27750000E+03 (277.5 ohm).

Refer to figure 2.1

MO Temperature element offset Format according to item LD. The offset represents the distancefrom the tank zero level to the lowest position of the MRT.

Note: Incase of ullage measurement, distance MO is taken from the upper reference point.

Commissioning


MI Switch hysteresis Format according to item LD. The distance MI is a hysteresisaround the switching point of the temperature elements.

MP Product immersion depth Format according to item LD. The distance MP specifies theminimum required liquid level above a element before it isselected for the average product temperature calculation.

MG Gas immersion depth Format according to item LD. The distance MG specifies theminimum required distance before the resistance value of thelongest element is taken in the average gas temperaturecalculation.

TU Temperature status conversion One ASCII character. Default this item is set to ”T“. If necessary,this item can be set to an other character.

2.3 Additional settings for an 877 FDI


OB Option board Three ASCII characters. This item informs the XPU what optionboard is installed. That can be:

• MPU (for MPU option board)• HPU (for HPU and OPU option board)

EG Enable temp. transm. One ASCII character; either “D” or “E”. With this item can beselected if the 877 FDI shall answer on a temperature request(C-record), addressed to the connected level gauge.

• E : transmission of temperature record enabled• D : transmission of temperature record disabled

TF Temperature source selection One ASCII character; either “I” or “E”. This item selects if thereis a temperature measurement inside the indicator (Internal) orto be fetched from the Enraf field bus (External).

• I : Internal (MPU, HPU or OPU option board installed)

• E : External

This concludes the commissioning of the 862 MIR temperature items.

Commissioning


2.4 Data items

There are of number of data items for the measured temperature, checks and status information. Thesedata items are:


AP Average product temperature This item contains the average product temperature, calculatedfrom the longest immersed element. It is preceded by fourstatus bytes from item MQ.

AG Average gas temperature This item contains the average gas temperature, calculatedfrom the longest element reduced with the average producttemperature influence. It is preceded by four status bytes fromitem MQ.

MQ Temperature status request This item contains four bytes with temperature statusinformation. For description of the status, refer to chapter 3.2.

MU Test resistance The measured test resistance in floating point format. The valueshould be: 370 ohm ± 0.03%.

U0 ÷ UC Calculated element positions Format according to item LD. These items gives theposition of each element with respect to the lowest partof the MRT.U0 : position of 1 element (0.25 m or 0.65 m)st

U1 : position of 2 element (0.65 m or 1.25 m)nd

| |UC : position of 13 element (22.95 m or 29.65 m)th

V0 ÷ VF Element temperatures Format according to item TD. These thirteen itemscontains the temperature of each element.V0 : temperature of 1 elementst

V1 : temperature of 2 elementnd

| |VC : temperature of 13 elementth

VV Temperature pointer value Internal floating point format. Refer to the item description ofitems VV and VP in chapter 5.

v w , x y Selected value

0 0 , 0 0 ÷ 1 2 Element resistance R ÷ R1 0 , 0 0 f_1 0 , 0 1 f_offset_1 0 , 0 2 R_1 0 , 0 3 Element being measured

1 13

Rref

Rref

cable

YP Stored average prod. temp. Format according to item TD. Stored product temperature,copied from item AP, after an ST command was given.

Error codes

3 Error codes

3.1 Temperature error MPU/HPU/OPU (item EM)

This item contains the most recent temperature error encountered by the MPU, HPU or OPU board.Error codes 22xx are from the MPU board, 24xx are from the HPU board and 26xx are from the OPU board.

2x00 No error, value at initialization 2x68 Overflow bit set in transmitted data. Check element2x50 Element 1 detected absent wiring connections2x51 Element 2 detected absent 2x69 CRC error in transmitted data )2x52 Element 3 detected absent 2x75 General MIR error (R_ref and / or R_gnd failed)2x53 Element 4 detected absent 2x78 Item MR not set to any value 2x54 Element 5 detected absent2x55 Element 6 detected absent2x56 Element 7 detected absent2x57 Element 8 detected absent2x58 Element 9 detected absent2x59 Element 10 detected absent2x60 Element 11 detected absent2x61 Element 12 detected absent2x62 Element 13 detected absent2x67 Wrong sequence number in transmitted data;

862 MIT will be reset )1

) Communication error with 862 MIR; check wiring and1

grounding between 862 MIR and connected instrument

1

2x80 Ratio R_test / R_ref invalid (should be 0.75)2x85 Negative element resistance. MRT element wrongly

connected or absent2x90 Floating point calculation failure (on processor board)2x92 No communication with MIR during last 10 seconds.

Check cabling between 862 MIR and connectedinstrument

2x93 Check the not connected element terminals. All notconnected terminals must be connected to ground(terminal CN4-16)

2x94 Cable resistance too high. Check the two black leadsof the MRT

2x95 Wrong type of element selected. Check item MT

3.2 Temperature status request (item MQ)

Four bytes status information (B0 B1 B2 B3) with the following meaning:

Status byte 0:Contains the characters ‘0’ ÷ ‘C’, indicating the highest immersed element of the MRT. At start up this is: ’I‘.

Status byte 1: Status byte 2:bit 0 : General temperature fail bit 0 : Last valid level used

1 : Fail in average product temperature 1 : Manual level used2 : Fail in average gas temperature 2 : Level time out3 : Level exceeds lowest element 3 : 04 : Level exceeds highest element 4 : 05 : Element fail (one or more elements defect) 5 : Out of specified temperature range6 : 1 6 : 17 : 0 7 : 0

Status byte 3: For decoding of the status bytes, refer to thebit 0 : No previous store command ASCII table in appendix A.

1 : Alternative (lower) element selected 2÷5 : 0

6 : 17 : 0

Specifications


4 Specifications

4.1 Mechanical

Dimensions height: 160 mm, width: 160 mm, depth: 90 mm (6 / " x 6 / " x 3 / ")5 5 916 16 16

Material aluminiumMechanical protection IP65Weight 2.2 kg (5 lbs)Mounting on top of the / " BSP threaded extension tube of MTT sensor1

2Optional rail or wall mounting

4.2 Electrical

Power supply the power supply is obtained by the 2 wire communication line from theoptional MPU, HPU or OPU board in the 854 level gauge, 877 FDI or873 SmartRadar.

4.3 Cabling

Cabling MIT to level gauge one twisted and shielded pair, R = 25 ohm. For the maximum valuesmax

or indicator of the capacitance and inductance, refer to the appropriate approvalcertificate.

Cable entries to associated instrument: standard PG16; with reducer to / " NPT or34

M20 x 1.5to 864 MTT: / " BSP (standard), or / " NPT (on rail) or / " NPSM or1 3 3

2 4 4PG16

4.4 Safety

Temperature connections intrinsically safe according to CENELEC EN 50.020 EEx ib IIB T4 forconnection to MPU, HPU or OPU option board (terminals CN6 1,2)intrinsically safe according to CENELEC EN 50.020 EEx ia IIB T4 forconnection to 864 MTT (terminals CN1 ÷ CN5)Ex-ia for Class I, Division 1, Groups C, D when connected to MPU, HPUor OPU optional board (Factory Mutual)Ex-ia for Class I, Division 1, Groups C, D when connected to MPUoptional board (CSA)

4.5 Accuracy

Combination 862 MIR ±0.2 °C (±0.35 °F) for temp. range: -20 °C to +100 °C (-4 °F to 210 °F)and 863 MRT ±0.45 °C (±0.8 °F) for temp. range: -50 °C to +200 °C (-60 °F to 390 °F)

4.6 Environmental

Ambient temperature -40 °C to +85 °C (-40 °F to +180 °F)Storage temperature -50 °C to +85 °C (-58 °F to +180 °F)

Item description

5 Item description

All items, related to the temperature measurement with the 863 MRT / 862 MIR, connected to the optionalMPU, HPU or OPU board are described in this chapter.

The items can be of the type N (Novram), D (data) or C (command).Novram items are stored in the NOVRAM on the XPU board of the instrument (for instance: element type,item MT).Data items contains measured and calculated data or error codes (for instance: average producttemperature, item AP). Data items are not stored in the NOVRAM and are lost after a reset or power down.Command items result in an action (there is only one command: store, item ST).

The protection level refers to the protection level 1 or 2 password which is required to issue them.

Item: AG Average gas temperature

Type: DProtection: no write accessDimension: determined by item TDDefault value: IF@@9999999

The average gas temperature is obtained by computing the resistance of the non-immersed part, minus length of item MG, from thelongest element. For the description of the 4 status bytes, refer to item MQ (chapter 3.2).

Item: AP Average product temperature


The average product temperature is calculated from the resistance of the longest immersed element.The longest immersed element is selected for the average product temperature if the level is above the element length + offset (itemMO) + product immersion depth (item MP). Refer to figure 2.1. For the description of the 4 status bytes, refer to item MQ (chapter 3.2).

Item: DP Decimal separator

Type: NProtection: level 2Entry format: one ASCII character; “.” (point) or “,” (comma)Default value: . (point)

With the decimal separator item, a selection can be made what character is to be used for the decimal separator in all settings andmeasured data for level, temperature, density and pressure. The decimal separator can be:

• . point• , comma

When the decimal separator is changed, all items which holds the decimal separator, must be changed to the new format.

Note:When the instrument is equipped with an XPU 2 board, the decimal separator is automatically changed in all related items.

The floating point format will always contain a point as decimal separator.

Item description


Item: EG Enable temperature transmission

Type: NProtection: level 2Entry format: one ASCII character; “E” or “D”Default value: E

This item Enables / Disables the 877 FDI to answer to a temperature request (C-record) from the host to the related level gauge.When enabled, the level gauge must not have installed a temperature option board.

If this item is set to “E” the addressed instrument does not answer to a temperature request. Instead the 877 FDI (with GA equals to theTA of the related level gauge) answers on a temperature request.

If this item is set to “D” the 877 FDI does not answer to a temperature request on a GA address.

Item: EM Error MPU request

Type: DProtection: no write accessDefault value: 2200 (with MPU board) 2400 (with HPU board) 2600 (with OPU board)

This item contains the most recent temperature error encountered by the MPU, HPU or OPU board. Description of the error code canbe found in chapter 3.1.

Item: FH Fatal HPU / OPU errors

Type: NProtection: no write accessDefault value: 00

This item counts the number of fatal HPU / OPU errors, detected by the XPU software. The maximum count is 99, additional errors arenot registered.

Item: FM Fatal MPU errors

Type: NProtection: no write accessDefault value: 00

This item counts the number of fatal MPU errors, detected by the XPU software. The maximum count is 99, additional errors are notregistered.

Item: H0 Last fatal HPU / OPU error

Type: DProtection: no write accessDefault value: 000:000

The first three bytes contains the last fatal error number which occurred just before the HPU / OPU board became unaccessible for theXPU. The last three bytes contains the number of 862 MIR resets as a result of lost communication or bad records.

Item: M0 Last fatal MPU error

Type: DProtection: no write accessDefault value: 000:000

The first three bytes contains the last fatal error number which occurred just before the MPU board became unaccessible for the XPU.The last three bytes contains the number of 862 MIR resets as a result of lost communication or bad records.

Item description

Item: MG Gas immersion depth

Type: NProtection: level 2Dimension: determined by item LDDefault value: +000.1000 (m) for 877 FDI

+000.5000 (m) for 854 level gauges and 873 SmartRadar

Distance MG is introduced to reduce the heat-transfer (via thermo-well) on the spot just above the product interface. Refer to figure 2.1.

Item: MI Switch hysteresis

Type: NProtection: level 2Dimension: determined by item LDDefault value: +000.1000 (m)

To prevent erratic readings by the on/off switching of temperature elements due to small level variations, a switch hysteresis isincorporated in selecting the elements. Refer to figure 2.1.

Item: MN Number of elements

Type: NProtection: level 2Entry format: two ASCII digitsDefault value: 16

Item MN specifies the number of elements connected to the 862 MIR (inclusive the spot element).The maximum number of elements which can be connected is 13 (i.e. 13 elements from an MRT without spot element, or 12 elementsfrom an MRT element with spot element).When an MRT is connected with a separate gas spot, then the maximum number of elements which can be connected is 11 (i.e. 11elements from an MRT without product spot element, or 10 elements from an MRT element with product spot element).A special case is when a dual spot element is connected (one product spot element and one spot element in the gas phase). Then itemMN becomes 01 with item MT set to Dxx, where xx is one of the following: PL, PS, NI, CB, CN or CS.

Item: MO Temperature element level offset

Type: NProtection: level 2 Dimension: determined by item LDDefault value: +000.0000 (m)

Distance MO defines the position of the lower end of the MRT with respect to the zero-level of the tank.For innage measurement, the switching level = actual level - MO; for ullage measurements, the switching level = MO - actual level (thisis exclusive the distances MP and MI). Refer to figure 2.1.

Item: MP Product immersion depth

Type: NProtection: level 2Dimension: determined by item LDDefault value: +000.5000 (m)

Distance MP is introduced to reduce the heat-transfer (via thermo-well) on the spot just below the product interface. Refer to figure 2.1and the description of item AP.

Item description


Item: MQ Temperature status request

Type: DProtection: no write accessDefault value: IF@@

This item contains 4 bytes with temperature status information. For description of the status, refer to chapter 3.2.

Item: MR Reference resistor

Type: NProtection: level 2Dimension: ohmEntry format: standard floating point formatDefault value: +.00000000E+00 (ohm)

This item contains the value of the reference resistor used in he 862 MIR. This value is: +.27750000E+03 (277.5 ohm).

Item: MT Temperature element type

Type: NProtection: level 2Entry format: three ASCII charactersDefault value: TPL

Item MT specifies the type of element connected to the 862 MIR. The length of this item is 3 bytes: C3 C2 C1, which have the followingmeaning:

C3: R refers to an MRT without spot elementQ refers to an MRT with spot elementD refers to an MRT with spot element and separate gas spot elementE refers to an MRT without spot element and separate gas spot element

C2 C1: SA Sangamo MRT; R = 90.4778 + (T x 0.3809) )th1

SS Sangamo spot; R = 90.5 + (T x 0.3873) )th1

BE Beacon MRT; R = 90.2935 + (T x 0.38826) )th1

BS Beacon spot; R = 90.2935 + (T x 0.38826) )th1

PL Pt100 large range (-200 ÷ +250 °C)PS Pt100 small range (-20 ÷ +120 °C)NI Ni191 (-20 ÷ +120 °C)CB Cu90 Beacon MRT; R = 90.2935 + (T x 0.38826) )th

1

CN Cu90 Nulectron MRT; R = 90.4778 + (T x 0.3809) )th1

CS Cu90 spot; R = 90.5 + (T x 0.3873) )th1

) T is temperature in degrees Celsius1

The temperature range for all copper elements is: -100 ÷ +280 °C.

Note:The dual spot configuration (C3 = D or E) is not supported by MPU A0.7 and A0.8 software version. Selecting this type, will result inan MPU start-up error (EP: 027).

Item: MU Test resistance

Type: DProtection: no write accessDimension: ohmDefault value: 99999999999999

This item contains the measured test resistance used in the 862 MIR.The value of this test resistor should be: 370 ohms ±0.03% (displayed as: +.37000000E+03; standard floating point format).

Item description

Item: OB Optional board

Type: NProtection: level 2Entry format: three ASCII charactersDefault value: TPU

This item informs the XPU board of the 877 FDI about the presence of an optional board. The following selections can be made:• MPU MPU board installed• HPU HPU or OPU board installed• - - - no option board installed

Item: ST Store

Type: CProtection: not protected

The store command copies all measured level and temperature data to the related stored items. Up on reception of the store command,the temperature data is stored as follows:

• Average product temperature (item AP) becomes: stored average product temperature (item YP)

Item: TD Temperature dimension

Type: NProtection: level 2Entry format: one ASCII character; “C” or “F”Default value: C

The temperature dimension can be set to:• C : temperature in degrees Celsius• F : temperature in degrees Fahrenheit

Both dimensions have the same format: sign X X X sep X X,where sign : + or -

X : digitsep : decimal separator (“.” or “,”)

Item: TF Temperature source selection

Type: NProtection: level 2Entry format: one ASCII character; “I” or “E”Default value: I

For the 877 FDI only. This item selects whether the temperature measurement is inside the indicator (by MPU, HPU or OPU optionboard) or outside (copied from the Enraf field bus). The settings are:

• I : internal by the MPU, HPU or OPU board• E : external from the related level gauge

Item description


Item: TU Temperature status conversion

Type: NProtection: level 2Entry format: one ASCII characterDefault value: T

The character “T” (default setting) in this item is used in the temperature status byte in the field communication to indicate a reduced ornot guaranteed temperature accuracy. Other characters can be used, if the host systems accepts them. The status byte is set if:

• out of specified temperature range• last valid level used• manual level used• level below lowest element• alternative element selected

Item: U0 .. UC Calculated positions of spot elements

Type: DProtection: no write accessDimension: determined by item LDDefault value: IF@@<level>

These 13 items contains the calculated elements lengths from the 863 MRT with respect to the lower end of the MRT. The distances ofitems MO, MI, MG and MP are not yet taken into account in items U0 .. UC. For details on the status bytes, refer to chapter 3.2.The table below gives the element lengths for MRT with spot element (MT=QXX) and MRT without spot element (MT=RXX).

Element MT = QXX MT = RXX Element MT = QXX MT = RXX

U0 0.25 (m) 0.65 (m) U7 7.35 (m) 9.25 (m)

U1 0.65 (m) 1.25 (m) U8 9.25 (m) 11.65 (m)

U2 1.25 (m) 1.95 (m) U9 11.65 (m) 14.65 (m)

U3 1.95 (m) 2.85 (m) UA 14.65 (m) 18.45 (m)

U4 2.85 (m) 4.15 (m) UB 18.45 (m) 22.95 (m)

U5 4.15 (m) 5.65 (m) UC 22.95 (m) 29.65 (m)

U6 5.65 (m) 7.37 (m)

Note:For MPU software version A0.8 and lower, these element lengths are for the spot 0.3 m and for the other elements 0.35 m higher.

Example:MO = 0.3 m, MP=0.5 m, MI=0.1 m.Element U4 (for an MRT with spot element) switches on at the level of: 2.85 + 0.3 + 0.5 = 3.65 m.

Item: V0 .. VC Element temperatures


These 13 items contains the temperature values of the individual elements. For details on the status bytes, refer to chapter 3.2.

Item description

Item: VP Value pointer

Type: DProtection: not protectedEntry format: two ASCII digits, point or comma, two ASCII digitsDefault value: 999999

The VP item consists of 4 positions, separated in the middle: v w , x y (or v w . x y).This item, together with item VV, makes it possible to request several important calculation results.By means of the value pointer, a vector can be loaded to the MPU, HPU or OPU board. Then, with item VV the selected value isreturned. For the temperature part of the MPU, HPU and OPU board, the following pointer values can be requested:

v w , x y Selected value Dimension

0 0 , 0 1 ÷ 1 2 Element resistance R ÷ R ohm1 0 , 0 0 f_ Hz1 0 , 0 1 f_offset_ Hz1 0 , 0 2 R_ ohm1 0 , 0 3 Element being measured

1 13

Rref

Rref

cable

Example: VP=00,03 (Value pointer for requesting the third element resistance)VV (Item VV holds the requested third element resistance)

Item: VV Pointer value

Type: DProtection: no write accessDimension: determined by item VPDefault value: 99999999999999

Item VV holds the measured value, selected by the value pointer item VP. For the contents of this item, refer to description of item VP.

Item: YP Stored average product temperature

Type: DProtection: no write accessDimension: determined by item TDDefault value: IF@A9999999

This item contains the ‘stored’ average product temperature value from item AP, at the time an ST command was issued.

Related documents


6 Related documents

Title Part no.

Installation guide 862 Temperature Selector 4416.232Installation guide 863 MRT Multiple Resistance Thermometer 4416.233

Installation guide 854 Advanced Technology Gauge 4416.225Instruction manual series 854 ATG level gauge 4416.220

Installation guide 854 XTG Servo Gauge 4416.276Instruction manual series 854 XTG level gauge 4416.275

Installation guide 873 SmartRadar Control Unit 4416.570Instruction manual 873 SmartRadar 4416.571

Installation guide 877 FDI Field Display & Interface 4416.259Instruction manual 877 FDI Field Display & Interface 4416.257

Appendix A

Appendix A

ASCII table:

862 MIR - Instruction Manual Vs30

Documents

Transcript of 862 MIR - Instruction Manual Vs30