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.
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.