Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual - Manual (Page 56)

Publication 1746-UM003A-EN-P
4-8 Channel Configuration, Data, and Status
Proportional Counts Data Format - If the user selects proportional counts data
format and uses the default limits of 0, 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:
The following illustration shows the linear relationship between output counts
and temperature when one uses proportional counts data format.
Figure 4.3 Linear Relationship Between Temperature and Proportional Counts
Temperature Counts
-200°C -32768
+630°C +32767
Counts
°C
630°C -200°C
-32768
+32767