Product Overview

S7-400 components

The most important components of the S7-400 and their functions are given in the following tables:

Components

Function

Illustration

Racks

... provide the mechanical and

 

(UR: Universal Rack)

electrical connections between

 

(CR: Central Rack)

the S7-400 modules.

 

(ER: Expansion Rack)

 

 

Power Supply Modules

... convert the line voltage

 

(PS = Power Supply)

(120/230 VAC or 24 VDC) to the

 

 

5 VDC and 24 VDC operating

 

Accessories:

voltages required to power the

 

Backup battery

S7-400.

 

CPUs

... execute the user program;

 

Central Processing Units (CPUs)

communicate via the multipoint

 

 

interface (MPI) with other CPUs

 

 

or with a programming device

 

 

(PG).

 

Memory cards

... store the user program and

 

 

parameters.

 

IF 964-DP interface module

... used to connect distributed

 

 

I/Os via PROFIBUS-DP

 

Signal Modules

... match the different process

 

(SM = Signal Module)

signal levels to the S7-400.

 

(digital input modules, digital

... form the interface between

 

output modules, analog input

PLC and process.

 

modules, analog output modules)

 

 

Accessories:

 

 

Front connector with three

 

 

different terminal systems

 

 

Interface modules

... interconnect the individual

 

(IM = Interface Module)

racks of an S7-400.

 

Accessories:

 

 

Connecting cable

 

 

Terminator

 

 

Cable ducts

...are used for routing cables and

 

 

as ventilation.

 

PROFIBUS bus cables

...connect CPUs to programming

 

 

devices.

 

1-2

Automation System S7-400

Hardware and Installation

 

A5E00850741-01

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Siemens installation manual S7-400 components, Components Function Illustration