Post on 22-Dec-2015
Thermocouple Signal Simulator
Sponsor: Emerson- Kent Burr, Charles Eastberg
Advisor- Dr. Semih Aslan
Group: NPPH(1.7)Taylor Nash, Rey Perez, Victor Pinones, and Travis
Howell
Why Emerson Needs A Thermocouple Signal Simulator
❖ Emerson has three different test teams in Round Rock
❖ They do different types of component testing, maxing out, and configurations
❖ Thermocouples is a very common component they test
❖ They want to be able to simulate thermocouple readings
❖ What does the Thermocouple Signal Simulator do?
Options❖ Input
➢ Multiple inputs➢ Configure thermocouple
types■ Input on DIP switches■ Software implemented
❖ Output➢ Have multiple outputs➢ Have just one output
Dataflow❖ Hardware implemented
➢ Need 8 of each components, one for each of the thermocouple types
➢ Too costly for hardware set up- not enough space, too many bugs
❖ Software implemented➢ Only need one processor
Components❖ Hardware
➢ Arduino Mega 2560➢ DAC, ADC➢ Electrical Isolator➢ 5V power supply➢ 4-20mA input➢ Power resistors➢ Op Amp➢ Printed Circuit Board
(PCB)
❖ Software
➢ Program to execute all logic and arithmetic
➢ Thermocouple Polynomial Library
➢ Thermocouple look-up tables
Proposal❖ Input
➢ 4-20mA, provided by Emerson
❖ Project: convert the 4-20mA signal into an isolated mV signal ranging from ±100mV
❖ Combination of mostly software and some hardware
❖ Configuration to each type of thermocouple
➢ 8 synchronized output nodes
Demo: Dataflow
Input4-20mA
Input range percentage conversion
Find relative temp. for
thermocouple
Use temp. for “look-up”
value
Map to PWM port
range
Output
BudgetDevice
Price
❖ Arduino Mega 2560.……………...$40❖ 5V High/Low Opto-isolator……....$8❖ PCB by TXST………………...…...$0❖ 24 bit ADC…………………………$11❖ 20 bit DAC ………………………..$20❖ 1-8 demultiplexer………………....$5❖ Project houseing………………....TBA
Total Estimated Price:$84
$200/memberTotal: $800
Test Plan
❖ Overview
➢ Input 4-20 mA signal
➢ Convert and isolate the input to eight ±100 mV outputs
➢ Outputs run to Emerson’s CHARM systems
Constraints❖ Economical
➢ Hardware implementation would be costly
➢ Wasteful of resources, i.e. all hardware would result in multiple components
➢ Processor/software implementation was much more practical
Dataflow Schematic Output Isolation
Hardware Selection
Hardware Purchase
Hardware Purchase
Timeline
Timeline
Program
DebugCircuit Assem
bly
Testing Softwar
e
Circuit Testing
System Testing
WriteProgram
CircuitAssembly
Deviation Handling
TestingSoftware
VerifySystem
Demo and Progress❖ Our demo simulates the type T thermocouple
❖ Input from Arduino’s serial interface
❖ Outputs analog signal on PWM port
❖ Similar to our completed system, except no isolation
References❖ htatp
://community.emerson.com/cfs-file/__key/communityserver-blogs-components-weblogfiles/00-00-00-02-92/3581.emerson_5F00_electric_2D00_logo.jpg
❖ http://upload.wikimedia.org/wikipedia/en/e/ed/Thermocouple_%28work_diagram%29_LMB.png
❖ http://www.ti.com/graphics/folders/partimages/ADS1675.jpg
❖ http://www.vetco.net/catalog/images/VET-SP-DIP3-1.jpg
❖ http://media.digikey.com/Renders/~~Pkg.Case%20or%20Series/DIP16_SOT38-1%20Pkg.jpg
Questions?