hello,
i am working on a big project where we work on redundant X20 PLC, the SCADA system is Zenon from Copa data, the connection between the PLC’s and the SCADA is OPC UA with highest level of encryption with certificates. the connection is made with one IP address to both PLC’s (bonding + cluster).
when a redundancy switch occur the connection is lost for almost 20 seconds.
what can i do to reduce the time significantly, it is not acceptable to lose data for 20 seconds.
please let me know if any more information needed.
thank you.
Do you have a configurable timeout option on the Zenon side?
Automation Help: Controller Redundancy Limitations
Communication connection
Only ANSL connections are redundancy-capable and can be switched automatically when a redundancy switchover occurs.
Other connections are also possible via the cluster IP address, but they normally have to be reestablished after a redundancy switchover.
When using OPC UA via the cluster IP address, the OPC UA in the rCPUs are not synchronized with one another.
It is also possible to set up two separate connections using the direct IP addresses of both rCPUs, which makes OPC UA access possible.
So If you don’t wan’t to lose data you need to connect to both CPUs independently and then select the source somewhere higher up.
As the connection needs to be re-established after a redundancy switchover, I believe it will take as long to change until your client side detects that it is no longer communicating.
regarding the timeout configuration i will need to check , but if it does have it, how should it help?
i don’t want to use 2 variables for each connection, this is a project with thousands of variables.
do you have any more suggestions?
It would cause the reconnection to happen faster.
OPC UA is not considered Redundancy capable (Ninjaedited my first answer to quote more from help), and this is why it does not trigger an automatic reconnection.
If there is a possibility on the Zenon side to force a reconnection. You could create separate connections to both PLC:s to monitor which one of them is active, and if it changes force a reconnection on the “main connection” to the cluster address, which would then reconnect to the active PLC again.
If not then there is not much you can do unless you are willing to go the way of the two separate connections.