Siemens Simatic S7-400

Configuration Variants of the S7-400
6-3
Automation System S7-400 Configuration and Use
A5E0044271 1-02
6.2 An Overview of S7-400 Components
Introduction
The S7-400 has a simple modular design. The most important components of an
S7-400 are described in this chapter.
Component Function Image
Racks
(UR = Universal Rack)
(CR = Central Rack)
(ER = Extension Rack)
Racks provide the mechanical
and electrical connections be-
tween the S7-400 modules.
Power supply modules
(PS = Power Supply)
Accessories:
Back-up battery
Power supply modules convert
the mains voltage ( 120/230 V
AC or 24 V DC) into the operat-
ing voltage required by the
S7-400, 5 V DC and 24 V DC.
CPUs
(CPU = Central Processing Unit)
CPUs execute the user program;
they communicate with other
CPUs and with programming de-
vices.
V4.0
Memory cards Memory cards are used to store
the user program and
parameters.
Interface module IF 964-DP The interface module IF 964-DP
is used to connect the distributed
I/O via ”PROFIBUS-DP
Signal Modules
(SM = Signal Module)
(digital input modules,
digital output modules,
analog input modules
analog output modules)
Accessories:
Front connectors with three differ-
ent connection systems
Signal modules adapt various
process signal levels to the
S7-400.
Signal modules form the inter-
face between the PLC and the
process.
Interface Modules
(IM = Interface Module)
Accessories:
Cable
Terminal plug
Interface modules interconnect
separate racks of an S7-400.
Cable duct The cable duct is used lay cables
and for ventilation.