Logs not updating with latest OPC data when softpoint servers switchover
To test redundancy of ASCS servers, we switched off ASCS-1.It was generally observed that ASCS-2 takes over immediately.However, once the softpoint service of ASCS-2 becomes SERVICE from STANDBY, all logs get stuck at the last data prior to switchover. The quality of the logs is good as reported in the Satus tab of a log's Log config aspect.The Trend curves get plotted with the same value every sample period.In RealPCA aspect the OPC value updates properly.
The only way we could restart logging with latest OPC tag value was by disabling and enabling the OPCda service provider of ASCS-2.
When doing this, the logged data becomes bad and then good again.Post this, upon re-reading the log config status, the logging resumes with updated values.
As the no of logs is few, synchronization is fast.
I have searched AKS for similar questions, but could not find anything wrt softpoint service switchover. Any suggestions or solution will be of great help.
Basic History only makes one subscription. No restart attempt, etc is made. If Max Time is set in Log Template, the last known value and status will be extrapolated if server does not send any update.
According to the OPC specification, a server must continue to update all clients until they remove their subscriptions.
Likely, the OPC server stopped fulfilling its duties.
Consider filing a support case with your regional ABB Support center.