Siemens SIMATIC User Manual

Principles of analog value processing
4.5 Wiring and connecting resistance thermometers and resistors
S7-300 Module data
248 Manual, 06/2017, A5E00105505-AJ
3-wire connection of a resistance thermometer (not for 6ES7331-7PF01-0AB0)
When connecting 3-wire devices to modules equipped with four terminals, you should
generally
bridge M- and I
C
-. Always wire and connect the connected
C
+ and M+ lines directly
to the resistance thermometer.
The image shows the basic wiring. Please observe the notes in the description about the
respective module.
Figure 4-10 3-wire connection of resistance thermometers to an electrically isolated analog input
2-wire connection of a resistance thermometerError! Bookmark not defined.
For 2-wire connections, insert a bridge between the M
+
and I
C+
and between the M- and I
C
-
terminals of the module. The line impedance is included in the measurement.
Figure 4-11 2-wire connection of resistance thermometers to an electrically isolated analog input

Siemens SIMATIC Specifications

General

Product type designation	SIMATIC
CPU	Varies by model
Memory	Varies by model
Input/Output	Varies by model
Communication	Varies by model
Programming Language	STEP 7
Operating Temperature	0°C to 60°C (varies by model)
Protection Class	IP20
Category	Programmable Logic Controller (PLC)