Rack
2
2.1
Function and design of the racks
Introduction
The racks for the S7-400 have the following functions:
● They physically hold the modules.
● They supply the modules with operating voltage.
● They connect the individual modules to each other via the signal busses.
Design 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
The following figure shows the mechanical configuration of a rack (UR1).
1
2
3
4
1
2
3
4
5
6
7
8
9
10 11
12 13 14 15 16 17 18
Figure 2-1
Configuration of a rack with 18 slots
(1)
Mounting rail
(2)
Plastic parts
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
27
