Siemens SIMATIC S7-1500 System Manual page 22

System overview
2.3 Components
Components
Load current supply
(PM)
22
The system power supply (PS), central modules (CPU), input and
output circuits of the I/O modules are supplied with 24 V DC through
the load current supply (PM). A load current supply does not occupy a
slot in the configuration and is not included in the system diagnostics.
If you are using load current supplies, we recommend the devices
from our SIMATIC series. These devices can be mounted on the
mounting rail.
You can configure the load current supply using STEP 7.
Load current supplies are available in various models:
PM 70W 120/230V AC
•
PM 190W 120/230V AC
•
Function Diagram
Automation system
System Manual, 12/2014, A5E03461182-AC