Siemens S7-1200 PROFIBUS Operating Instructions Manual page 21

Power supply
The device is designed for operation with a directly connectable safety extra low voltage
(SELV) from a limited power source (LPS).
The power supply therefore needs to meet at least one of the following conditions:
• Only safety extra low voltage (SELV) with limited power source (LPS) complying with IEC
• The power supply unit for the device must meet NEC Class 2 according to the National
If the equipment is connected to a redundant power supply (two separate power supplies),
both must meet these requirements.
Prior to installation and commissioning
Read the system manual "S7-1200 Programmable Controller"
Prior to installation, connecting up and commissioning, read the relevant sections in the
system manual "S7-1200 Programmable Controller" (references to documentation in the
Appendix).
When installing and connecting up, keep to the procedures described in the system manual
"S7-1200 Programmable Controller".
Make sure that the power supply is turned off when installing/uninstalling the devices.
Configuration
One requirement for the commissioning of the CP is the completeness of the STEP 7 project
data. You should also read the section "Configuration and program blocks (Page 27)".
SIMATIC CM 1242-5
Operating Instructions, 01/2023, C79000-G8976-C245-06
WARNING
60950-1 / EN 60950-1 / VDE 0805-1 or IEC 62368-1 / EN 62368-1 / VDE 62368-1 may be
connected to the power supply terminals.
Electrical Code (r) (ANSI / NFPA 70).
WARNING
Installation, connecting up, commissioning
3.3 Installing, connecting and commissioning
21