Redundant I/O In The Switched Dp Slave - Siemens SIMATIC S7-400H Manual

Using I/O on the S7-400H

3. Redundant I/O in the switched DP slave

The signal modules are installed in pairs in the distributed I/O device ET 200M
with active backplane bus.
Figure 7-5
7-12
Redundant I/O in the switched DP slave
Redundant module pair
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07