karkeraashwith - 2018-02-22

I have an OPC server & a opc client in same Win7 PC with 20 VPB40 controllers configurations. Everything runs smooth. But when any one Controller goes off or shutdown or disconnected from network, then sometimes all PLC's gets disconnected from OPC, sometimes few PLC's gets disconnected and sometimes only respective PLC gets disconnected from OPC server. And other than actual disconnected plc, rest of them will get reconnected automatically. The OPC sever running version is 1.61.238.3 on both Controllers(xp) as well as PC. I have tried several timeout, wait time and re connection time configurations. But none are helping. Currently those are 5000, 30,30 respectively.

Below is the OPCLog

(22.02.2018, 14:19:59.332) * ERROR: COMM_FATALERROR[0] from <plc1>
(22.02.2018, 14:20:04.332) </plc1>
ERROR: Sync reading values failed from <plc1>, Timeout expired
(22.02.2018, 14:20:04.363) * ERROR: COMM_FATALERROR[0] from <plc1>
(22.02.2018, 14:20:09.364) </plc1>
</plc1>
ERROR: Sync reading values failed from <plc2>, Timeout expired
(22.02.2018, 14:20:14.378) * ERROR: Sync reading values failed from <plc6>, Timeout expired
(22.02.2018, 14:20:19.391) </plc6>
ERROR: Sync reading values failed from <plc9>, Timeout expired
(22.02.2018, 14:20:24.408) * ERROR: Sync reading values failed from <plc15>, Timeout expired
.
.
(22.02.2018, 14:21:44.711) </plc15>
</plc9>
ERROR: HandleReply: * PLC(4)=PLC2 is in unnormal state State=OCS_IDLE (OCS_IDLE)!
(22.02.2018, 14:21:44.711) * ERROR: HandleReply:
PLC(5)=PLC6 is in unnormal state State=OCS_IDLE (OCS_IDLE)! *
(22.02.2018, 14:21:44.711)
ERROR: HandleReply: * PLC(10)=PLC9 is in unnormal state State=OCS_IDLE (OCS_IDLE)!
(22.02.2018, 14:21:44.711) * ERROR: HandleReply: PLC(20)=PLC15 is in unnormal state State=OCS_IDLE (OCS_IDLE)! ***
.
.</plc2>

Have you come across such issue? can anyone pls support?