What this cable does in an S7-300 rack
The Siemens 6ES7368-3AF00-0AA0 is the S7-300 connecting cable that links an IM360 interface module in one rack to an IM361 interface module in an expansion rack, carrying the I/O bus between the two. This cable is specific to the S7-300 rack architecture — it does not connect to an S7-400 rack.
Compatibility and fit
The cable connects the IM360 in the central rack to the IM361 in the expansion rack — both modules are part of the S7-300 system and the cable carries the bus signals between them.