AC800M OPC sever capacity
Inviting experts here to give some practical insights to help me understand capacity of AC800M OPC server. How do I know if it can handle 40,000 active items, 3500 items changing per second, 9000 Basic History points. Got 10 controllers with total system load varying between 50 to 80 %. Any other boundary line I need to check?
(P.S.: Please do not ask to refer system guide. It is already as confusing as it could be. Wish it could be more elaborative backed up with examples.).
I've been told that the AC 800M OPC server alone has very high capacity limits.
If all clients stick to the lean asynchronous OPC methods and cached reads where possible (as the 800xA DA Connector service will when servicing normal internal clients within 800xA) limits should be very high (in theory only restricted to how many COM callbacks the host CPU can deliver to clients given that the network layer is fast enough handling the downstream MMS traffic)
I believe the system guide limit in 5.x was 2.000 but with release of 5.1 it became tenfolded, ie 20.000 callbacks per second. That is A LOT!
Bottleneck should be how much reserve CPU capacity you have left in your AC 800M in terms of handling MMS reads from the OPC server. Normally the controllers saturates before the OPC server.
Low cyclic load and proper Task Tuning is most likely a foundation pillar here.
I can only agree to the shortcomings of the system guide. However, testing and writing a performance spec is a challenging task especially if it should handle a variety of different client behaviours and code design and execution in the AC 800M. One bad client or poorly tuned code block in the controller could have drastic effects.
Im going to echo Stefans answer here. Ive never seen an 800xA system where the OPC server was the bottle neck. You're going to run out of CPU load in the controller or Disk Write capacity on the history storage server before you run into limits on the OPC server.
And if it cannot handle 10 controllers then it is very simple to add another OPC server and split into 2 groups of 5.