Siemens SIMATIC S7-400 Reference Manual page 326

Interface modules
6.1 Common features of the interface modules
Connection possibilities for central racks and expansion racks
Central controller
326
IM 460-4
IM 460-3
IM 460-1
IM 460-0
Expansion without 5-V transmission at local range
Expansion device EC 1
IM 461-0
Expansion with 5-V transmission in local range
Expansion device EC 1
IM 461-1
Line length max. 1.5 m
Expansion in plant-wide field environment
Expansion device EC 1
IM 461-3
Expansion device EC 1
IM 461-4
Expansion device EC 4
Line length max. 5 m
Expansion device EC 4
Line length max. 102.25 m
Expansion device EC 4
Line length max. 605 m
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
IM 461-0
IM 461-3
IM 461-4