Siemens S7-400 installation manual Connecting the CR and ERs, Connecting with a 5 V Supply

Installing the S7-400

Connecting the CR and ER(s)

To connect one or more ERs to a CR, you must fit one or more send IMs in the CR.

The send IMs have two interfaces. You can connect one chain of up to four ERs to each of the two interfaces of a send IM in the CR.

Different IMs are available for local connection and remote connection.

Connecting with a 5 V Supply

For a local connection with the IM 460-1 and IM 461-1, the 5 V supply voltage is also transferred via the interface modules. There must therefore be no power supply module inserted in an ER connected to an IM 460-1/IM 461-1.

Up to 5 A may flow through each of the two interfaces of an IM 460-1. This means that each ER connected via an IM 460-1/461-1 can be powered with a maximum of 5 A at 5 V. For further details, see the Reference Manual, Chapter 6.

Overview of the Connections

Observe the connection rules at the end of this section.

	Local Connection		Remote Connection
Send IM	460-0	460-1	460-3	460-4
Receive IM	461-0	461-1	461-3	461-4
Max. number of connectable	4	1	4	4
EMs per chain
Max. distance	5 m	1.5 m	102.25 m	605 m
5 V transfer	No	Yes	No	No
Max. current transfer per inter-	--	5 A	--	--
face
Communication bus transmission	Yes	No	Yes	No

Automation System S7-400	Hardware and Installation	2-3
A5E00850741-01