beautypg.com

Siemens Simatic S7-400 User Manual

Page 366

background image

Interface Modules

6-4

S7-400, M7-400 Programmable Controllers Module Specifications

A5E00069467-07

Rules for Connection

When you connect a central rack to expansion racks, you must observe the
following rules:

You can connect up to 21 ERs of the S7-400 to one CR.

The ERs are assigned numbers to identify them. The rack number must be set
on the coding switch of the receive IM. Any rack number between 1 and 21 may
be assigned. Numbers must not be duplicated.

You may insert up to six send IMs in one CR. However, only two send IMs with
5 V transfer are allowed in one CR.

Each chain connected to the interface of a send IM can comprise up to four ERs
(without 5 V transfer) or one ER (with 5 V transfer).

The exchange of data via the communication bus is limited to 7 racks, meaning
the CR and ER numbers 1 to 6.

The maximum (total) cable lengths specified for the type of connection must not
be exceeded.

Connection type

Maximum (total) line

length

Local connection with 5 V transfer via IM 460-1 and IM 461-1

1.5 m

Local connection without 5 V transfer via IM 460-0 and IM 461-0

3 m

Remote connection via IM 460-3 and IM 461-3

102.25 m

Remote connection via IM 460-4 and IM 461-4

605 m

Terminator

The bus must be terminated in the last EU of a line. To do this, plug in the
appropriate terminator in the lower front connector of the receive IM in the last EU
of the line. Unused front connectors in a send IM do not have to be terminated. The
IM 461-1 with the order number 6ES7 461-1BA01-0AA0 does not require a
terminator.

Table 6-2

Terminators for the Receive IMs

Receive IM

Terminator

IM 461-0

6ES7461-0AA00-7AA0

IM 461-1

6ES7461-1BA00-7AA0

IM 461-3

6ES7461-3AA00-7AA0

IM 461-4

6ES7461-4AA00-7AA0

This manual is related to the following products: