Step7 Soft Redundancy BackUP Link Break

Join Date
Jun 2005
Posts
54
Hi All,

We are using S7300 CPU 317-2DP with Software Redundancy. The Backup link for Redundancy is via Ethernet.
Suppose PLC-A is Master and PLC-B Reserve.
When PLC-A Master running and if the Redundant Backup Link Ethernet Cable break, then PLC-B will not take over as Master but the Instance DB.DBW8 gives status as Master on both PLC but the only difference on PLC-B that it sets the Instance DB.DBX9.5 = 1 which means Redundant Backup link failed. But the PLC-B processor never connects to DP Slaves,still PLC-A connects to DP slaves.

I tried to set the bit Instance DB.DBX10.0 which means acivate the Master-Reserve Changeover. But PLC-B never takeover DP slaves as Master.

In this condition both PLC Status is Master and the Master PLC-A whose link cable break remains Master with DP Slaves.

Is there any way that I can Switch PLC-B to become Master and PLC-A Reserve when the link are broken.

Attached is the picture for wireless Access Point which has same problem as for DP slaves.

All your suggestions and solutions are highly appreciated.

Best Regards,
Pramod

connection11111.JPG
 
Last edited:

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