Communication
14.6 Communication via fault-tolerant S7 connections
S7-400H
System Manual, 03/2012, A5E00267695-11
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Response to failure
Double errors in the fault-tolerant system (i.e. CPUa1 and CPa2) and failure of the PC result
in a total failure of communication between the systems involved (see previous figures).
PC/PG as Engineering System (ES)
To be able to use a PC as Engineering System, you need to configure it under its name as a
PC station in HW Config. The ES is assigned to a CPU and is capable of executing STEP 7
functions on that CPU.
If the CPU fails, communication between the ES and the fault-tolerant system is no longer
possible.