What it is and what it does
The Siemens 6ES7461-0AA00-0AA0 is an IM461-0 receiver interface module for the SIMATIC S7-400 rack. It handles centralized connection without power supply transmission over the K bus — meaning it links expansion racks to the central controller but expects each rack to have its own power supply rather than drawing it over the bus cable.
Where it fits in the rack
The IM461-0 receiver sits in the expansion rack of an S7-400 system, receiving the K-bus link from the central controller's IM460-0 sender. No power supply transmission means each expansion rack needs its own PS module — a common configuration for larger systems where bus-powered racks would hit voltage drop limits. The module occupies one slot in the S7-400 rack and connects via the backplane K bus.