I want to understand how the redundancy of the DeltaV OPC Mirror works.
Let say we have the following:
DV_APPSTN_P = Primary DV Application Station
DV_OPC_P = Primary DV OPC Server
DV_OPCM_P = Primary DV OPC Mirror
3rd_Party1_OPC_P = Primary 1st 3rd Party OPC Server
DV_APPSTN_S = Secondary DV Application Station
DV_OPC_S = Secondary DV OPC Server
DV_OPCM_S = Secondary DV OPC Mirror
3rd_Party1_OPC_S = Secondary 1st 3rd Party OPC Server
3rd_Party2_OPC = 2nd 3rd Party OPC Server (Non-redundant)
Question: What will happen to the OPC communication with regards to 1st 3rd Party OPC Server (Active) if the 2nd 3rd Party OPC Server fails? Or is this above configuration possible?
In reply to Neil Castro:
In reply to Rein:
To Alec and Neil, Please note when you implement your watchdog logic in OPC mirror that the watchdog should be the last pipe of each respective device. My experience is old so I'm not sure it is still valid, but it is important. We were communicating over OPC mirror with multiple PLCs. We added more points to our plant-wide PI database and went over our OPC license. When this happened, the registers in the last pipe of the last device stopped updating. We were no longer receiving new information on the analog registers of a PLC controlling a vacuum pump. The heartbeat was implemented in an earlier pipe and it was updating correctly. Our "heartbeat" was fine, but our analog data was stale. I do not remember seeing an OPC error in OPC Mirror when our analog data in the last pipe stopped updating. This might not be a problem for you, but it would be better to anticipate this and plan for it in advance than to be surprised by it.
Hello Neil, In the OPC Server Monitor Configuration, there are 2 options for Enabling the OPC Mirror Redundancy Monitoring. One is "Failure on ANY Server" and the other is "Failure of ALL Servers. The " Failure on ANY Server" is selected because we have an existing redundant 3rd party OPC Server. What do you mean by this? Does this overwrites the logic on the watchdog?
Or do I need to install Simplex OPC Mirror on the simplex 3rd Party OPC Server?
If yes, will there be any conflict with the other OPC Mirror installed in the redundant DeltaV OPC Server?
Regards,
Hello again Neil, Yes, by default, the server monitoring is disabled. But it's enabled because we have other redundant 3rd party OPC servers connected. Therefore, connecting other simplex 3rd party OPC server to both the Active and Standby OPC Mirror is not ok. Regards.
It's been a while Neil. Just an update. The OPC Server Monitor Configuration is set to "Failure of ALL Servers will switch-over the OPC Mirror from Active to Stand-by". This will also overrides the watchdog. To summarize, it is just ok to connect a simplex 3rd party OPC Server to a redundant OPC Mirror. Watchdog is not necessary at all for the simplex OPC Server as it has of no use since if it fails, all data will be lost from this simplex 3rd party OPC Server.
Mod, please mark this thread as answered. Thanks.