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1 function and structure of the racks – Siemens Simatic S7-400 User Manual

Page 72

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Racks

2-2

S7-400, M7-400 Programmable Controllers Module Specifications

A5E00069467-07

2.1

Function and Structure of the Racks

Introduction

The racks in the S7-400 have the following tasks:

They hold the modules

They supply the modules with operating voltage

They connect the individual modules to each other via the signal buses

Structure of the Racks

A rack consists of the following elements:

Mounting rail with threaded bolts for fixing the modules and lateral cutouts for
mounting the rack

Plastic parts that function, among other things, as guides when swinging the
modules into place.

A backplane bus, an I/O bus and, if necessary, a communication bus with bus
connector

Connection for local ground

Figure 2-1 shows the mechanical configuration of a rack (UR1).

Aluminum carrier

Plastic parts

Connection for local ground

Bus connector (covered when shipped)

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15 16 17 18

Figure 2-1

Structure of a Rack with 18 Slots

UL/CSA Note

Special requirements should be taken into consideration in the area of influence of
the UL/CSA; these may be fulfilled by installing the system in a cabinet.

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