Configuration With Isolated Modules - Siemens SIMATIC S7-300 Hardware And Installation Manual

Configuring
Example:
The figure below shows a sample configuration: One CPU 31xC or 312 IFM with
isolated modules.
L1
L1
N
N
PE
Ground bus in
cabinet
L +
M
external
DC 24 V load power supply
* In the case of CPU 31xC or 312 IFM, the connection is automatically established.
Figure 5-11 Configuration with isolated modules
Non-isolated modules
In configurations with non-isolated modules, the reference potentials of the control
circuit (M
internal
figure below ).
5-24
PS S7-300 CPU
µ P
*
L +
M
) and load circuit ( external) are not electrically isolated (see the
M
DI DO
AC 230 V load
power supply
S7-300 Programmable Controller Hardware and Installation
U
internal
Data
M
internal
L1
N
A5E00105492-02