Siemens SIMATIC Manual page 570

Parameter sets of signal modules
A.11 Parameters of analog input module SM 331; AI 6 x TC isolated
Figure A-24
Note
The representation of limits matches the analog value representation. When defining limit
values, take the measuring range limits into account.
Temperature measurement
The table below contains the coding you must enter at byte 0 of data record 1 for the various
temperature measurements.
570
Data record 128 for AI 6 x TC
Temperature unit for linearization
Celsius
Fahrenheit
Kelvin
Code
2#00
2#01
2#10
S7-300 Module data
Manual, 06/2017, A5E00105505-AJ