OpcDA overload event - advant master
Hi we have 800 xa rev E with advantage master connectivity, we are facing dynamic points failure in the system from yesterday, we have restarted opcda service to resume the live data.
I have observed that "opcda overload event" in workplace structure.
What is the meaning of this event exactly, what went wrong in the system, pls suggest.
The event is new and becomes triggered when idle time in the OPC server for MB300 becomes too low (which happen when OPC traffic is too high)
The MB300 network and communication was developed in the 1980-ies for a handful of operator stations and occasional operator input. The design is sensitive for improper subscriptions and frequent write commands - a top modern OPC server in 800xA can not compensate for the design limitations in the Advant/Master PLCs.
Suggest reading the performance sections of:
- 800xA for Advant Master Configuration User's Guide
- 800xA for Advant Master Performance Guideline
Ensure subscribers only use Advise() based asynchronous subscriptions on 1, 3 or 9 second update rate and only to attributes for which true cyclic subscription is supported (see config guide for a listing). The volume of writes should be kept to a minimum and only target objects of MB300 DAT type. Max recommended RTA load (if operators are to use/share the OPC server) is 40-50%.
If possible, use the CI855 MB300 communication module of AC 800M to offload high performance communication via AC 800M. The AC 800M OPC server is far better suited than the Advant Master counterpart.
If you want my input, revert with the following for each AC400 Connectivity Server/RTA/PU410:
1) ANPER Channel Utilization Analyze
2) ANPER Task Load Analyze
3) System Messages seen in RTA Board Config/OnLine Builder
4) OPC DA Connector statistics operation in applogviewer
5) OPC DA MasterAdapter statistics operation in applogviewer