Dear all, 

Recently I found out that Step 7 V5.6 HF 4 and HF 5 unable to insert a 4-subconnections S7 fault tolerant connection. Only V5.6 HF 3 can do so. 

HF4 and 5 can only insert a 2-subconnectiotn S7 fault tolerant connection. 

CPU a R0- CPU b R0

CPU a R1-CPU b R1. 

R0 - R1 or R1 to R0 , connection will be down. 

Thanks, explained a lot now.

Had this issue now and trying to solve it in SP2 hf 5, still won't make 4 connections.

Is Siemens aware of this issue?