Siemens SIMATIC S7-1200 System Manual page 1089

Hide thumbs Also See for SIMATIC S7-1200:

Table of Contents

The CB 1241 provides internal resistors for terminating and biasing the network. To

terminate and bias the connection, connect TRA to TA and connect TRB to TB to include the

internal resistors to the circuit. CB 1241 does not have a 9-pin connector. The following table

shows the connections to a 9-pin connector on the communications partner.

Termination and bias for the CB 1241

Terminating device (bias ON)

Connect M to the cable shield

A = TxD/RxD - (Green wire / Pin 8)

B = TxD/RxD + (Red wire / Pin 3)

S7-1200 Programmable controller

System Manual, V4.2, 09/2016, A5E02486680-AK

Communication processor and Modbus TCP

13.2 Biasing and terminating an RS485 network connector

Non-terminating device (bias OFF)