Siemens Simatic S7-400 - Manual (Page 387)

IM 463-2
7-3
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
7.2 Rules for Connecting S5 Expansion Units
Introduction
When you connect S5 expansion units to an S7-400 via the IM 463-2, there are
rules to observe with regard to cable length, maximum expansion, use of a
terminating connector and permissible potential differences.
Cable Length
The maximum cable length per IM 463-2 from the CR of the S7-400 to the last
S5 expansion unit is 600 m. You set the actual cable length at the IM 463-2
(see Section 7.3).
Maximum Expansion
You can use up to four IM 463-2s in one S7-400 CR.
At each IM 463-2 interface (C1 and C2), you can connect up to four S5 expansion
units in a distributed configuration.
You can connect further EUs centrally to the EUs connected in the distributed
configuration.
Addressing of the S5 modules
All S5 address areas are available (P, Q, IM3, IM4)
Note
Note that every S5 address can only be used once, even across different chains.
Terminating Connector
You must terminate the IM 314 of the last EU in each chain with the
6ES5760-1AA11 terminating connector.
Permissible Potential Differences
For the safe functioning of the distributed configuration, you must ensure that the
potential difference between two devices is not more than 7 V. Use an equipotential
bonding conductor.