IM 360/IM 361 and IM 365 modules support a multitier configuration of the S7-300 automation system (CPU 313C, CPU 314 or later), consisting of a central controller (CC)and up to three expansion racks (ERs).

The individual racks are interconnected via the interface modules.

• IM 365:
  Central controller and 1 expansion rack each with max. 8 modules; Distance: 1 m
• IM 360/IM 361:
  Central controller and max. 3 expansion racks each with max. 8 modules; Distance between two adjacent racks: 4 cm to 10 m