Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual - Manual (Page 98)

Publication 1746-UM003A-EN-P
7-6 Application Examples
Program Setup and Operation Summary
1. 1. 1. 1. The alarms section of the ladder program monitors for any out of range
condition.
2. 2. 2. 2. Set up two configuration words in memory for each channel, one for °C
and the other for °F. The following table shows the configuration word
allocation summary.
Table 7.4 Configuration Word Allocation
3. 3. 3. 3. When the position of the degrees selector switch changes, write the
appropriate channel configuration to the RTD module. Note that the use
of the OSR instruction (one-shot rising) makes these configuration changes
edge-triggered, that is, the RTD is reconfigured only when the selector
switch changes position.
4. 4. 4. 4. Convert the individual RTD data words to BCD and send the data to the
respective LED displays.
Program Listing
The first two rungs of this program send the correct channel setup information
to the RTD module based on the position of the degrees selector switch.
Channel Configuration Word Allocation
°F
°C
0 N10:0 N10:8
1 N10:1 N10:9
2 N10:2 N10:10
3 N10:3 N10:11
4 N10:4 N10:12
5 N10:5 N10:13
6 N10:6 N10:14
7 N10:7 N10:15