Wiring Front Connectors; Assignment Of Front Connectors To Modules - Siemens SIMATIC S7-300 Hardware And Installation Manual

Wiring
7.5

Wiring front connectors

Introduction
The front connector is used to connect the sensors and actuators of your system to
the S7-300 PLC. Wire the sensors and actuators to this front connector and then
plug it into the module.
Front connector versions
Front connectors come in 20-pin and 40-pin versions, each with screw contacts or
spring terminals. 40-pin front connectors are required for CPUs 31xC and 32-
channel signal modules.
You must use the following front connectors, depending on the module:
Table 7-4
Module
Signal modules
(not 32-channel),
Function modules,
Communication module
CP 342-2
CPU 312 IFM
Signal modules
(32-channel)
CPUs 314 IFM and 31xC
Termination with spring terminals
To terminate a conductor in a front connector with spring terminals, simply insert
the screwdriver vertically into the opening with the red opening mechanism, insert
the wire into the terminal and remove the screwdriver.
Warning
You can damage the spring-based opening mechanism of the front connector if the
screwdriver slips sideways or if you insert the wrong size of screwdriver. Always
slide a suitable screwdriver vertically into the desired opening until it reaches the
stop. This will ensure that the spring terminal is fully open.
Tip:
There is a separate opening for test probes up to 2 mm in diameter to the left of the
opening for the screwdriver.
7-8

Assignment of front connectors to modules

Front connectors with
screw terminals; Order
No.:
6ES7 392-1AJ00-0AA0
6ES7 392-1AM00-0AA0
S7-300 Programmable Controller Hardware and Installation
Front connectors with
spring terminals; Order
No.:
6ES7 392-1BJ00-0AA0
6ES7 392-1BM01-0AA0
A5E00105492-02