Software Redundancy CPU MLFB Different.

SIMATIC S7-300/S7-400 Software redundancy for SIMATIC S7

3.2 What hardware is required?

Two S7-300 and/or S7-400 stations form the core of hardware requirements and are each equipped with a CPU and a connection for a DP master system.

The two stations are linked by means of a bus system that you can use to exchange data.

The I/O devices are interconnected by way of two DP master systems: One DP master system on station A and on one station B.

ET 200M distributed I/O devices with redundant DP slave interface module IM 153-2 are connected to DP master systems. The DP slave interface module allows the failover from the first to the second interface in the event of a fault in order to forward process status data from the second DP master to the I/O.

Hope this helps,
Daniel Chartier