Rockwell Automation 1746-NR4 SLC RTD/Resistance Input Module User Manual - Manual (Page 69)

Publication 1746-UM008B-EN-P - December 2006
Channel Configuration, Data, and Status 69
The Linear Relationship Between Temperature and PID Counts graph
shows the linear relationship between output counts and temperature
when one uses scaled–for–PID data format.
Linear Relationship Between Temperature and PID Counts
Proportional Counts Data Format
If the user selects proportional counts data format, the data word for
that channel is a number between -32,768 and 32,767. This provides
the greatest resolution of all scaling options. The value -32,768
corresponds to the lowest temperature value of the RTD type or the
lowest resistance value (ohms). The value 32,767 corresponds to the
highest temperature value for that RTD or the highest resistance value
(ohms). For example, if a 100
Ω Platinum RTD (3916) is selected, then
the relationship of temperature and module counts is shown in the
following table.
The Linear Relationship Between Temperature and Proportional
Counts graph shows the linear relationship between output counts
and temperature when one uses proportional counts data format.
Relationship Between Temperature and Counts
Temperature Counts
-200 °C (-328 °F) -32,768
+630 °C (1166 °F) +32,767
16383
630 °C
°C
Counts
±200 °C