Siemens SIMATIC ET 200M Operating Instructions Manual page 47

Installation Options
Dependent on the length of the rails you can fit up to 9 active bus modules:
Figure 3-9
Placement of the PS 307 power supply modules
Redundancy with 2 x IM 153-
2
IM 153-1 /-2 for "Module
change in operation"
See also
Order Numbers for the ET 200M (Page 247)
ET 200M
Operating Instructions, 04/2022, EWA-4NEB7806006-09
Configuration with active bus modules
If you use the 530 mm rail, place the BM IM/IM in the right-hand of the
two latched positions on the rail Then you can install either 2 x PS 307;
2A or 1 x PS 307; 5A to the rail to the left of the BM IM/IM.
Otherwise you must fit the power supply modules to a separate S7
standard rail.
Recommendation: Each IM 153-2 has its own PS.
Alongside the IM 153-x, the PS 307; 2A is also compatible with the BM
PS/IM.
The PS 307; 5A or 10A are not compatible with the BM PS/IM. You
must fit these to a separate S7 standard rail.
Assignment planning
3.5 Configuring the mechanical structure
47