Rockwell Automation 1746-INT4 Thermocouple/MV Isolated/ User Manual - Manual (Page 75)

Publication 1746-UM614B-EN-P - September 2007
Application Programming Examples 75
Program Setup
Follow these steps to set up the program.
1. Set up two configuration words for each channel in file N10, one
for °C and the other for °F.
Include two configuration words for the CJC temperature in the
cabinet containing the SLC controller.
2. Write ladder logic to send channel configurations to the module
when the operator changes the °C/°F or the ambient/cabinet
selector switch.
The OSR instruction (one-shot rising) makes these configuration
changes edge-triggered. That means the module is reconfigured
once each time the operator changes a switch position.
3. Write ladder logic to monitor the channel 0 status word to
determine whether ambient or cabinet temperature is being
displayed, and energize the appropriate pilot light.
4. Write ladder logic to convert thermocouple data words to BCD
and send them to the LED indicator displays.
N10 Channels/Configuration Words
Channel Configuration Word Addresses
°F °C
0 N10:0 N10:4
1 N10:1 N10:5
2 N10:2 N10:6
3 N10:3 N10:7
CJC N10:8 N10:9