Do I Need a Power Supply in a Siemens S7 Expansion Rack with IM365 Interface Module

[Simmo_in_Oz]

G'day, I'm trying to find a definitive answer to the following.

If an IM365 interface module is fitted in an expansion rack can a power supply be fitted to that expansion rack to provide extra power, such as a PS307 or is all power for the expansion rack supplied solely from the IM365 - in other words a power supply cannot be fitted to the external rack? The Siemens documentation doesn't really clarify and appears to contradict in some places.

Cheers

 

[JesperMP]

You dont need to fit a PSU in slot 1 of the expansion racks.
As a matter of fact, you dont need to fit a PSU in slot 1 of the central rack (with the CPU) either !
Precisely, there is no "slot 1" in S7-300. It is just an idiotic placeholder for a 24V PSU with S7-300 form-factor. The S7-300 just needs 24V from somewhere.
Power to outputs is always supplied to terminals on the output modules themselves, the power that is sent via the IM365 is just the 5V for the internal electronics. In other words it is plug and play, you dont have to worry about the power draw over the IM365.

 

[Simmo_in_Oz]

Many thanks