I
C+
Constant current line (positive)
I
C-
Constant current line (negative)
M
+
Measuring line (positive)
M
-
Measuring line (negative)
Analog modules
5.12 Connecting resistance thermometers and resistors
S7-400 Automation System Module Data
214 Reference Manual, Ausgabe 11/2016, A5E00850736-08