Our application station has three OPC DA servers running on it, including the built in DeltaV OPC DA server. The other two are for systems that we need to exchange data with.
We use Kepware as a client that reads data, from the two DA servers, and then writes this data to the DeltaV OPC server. (We also write data from DeltaV back to these servers but that seems to work fine) This is accomplished using linked tags in the Kepware advanced tags.
We are reading around 2500 tags from each of the two systems. The issue is that we frequently get write failures to the DeltaV OPC DA server.
I came across this post today RE: OPC DA clients number limit
Could the 2K Writes per second limitation be the cause of our troubles?
In reply to LaurentB:
Thanks for the reply. I can confirm that our client is using Asynchronous writes. I am dong some testing on a spare application station (live system) and have found that the writes begin to fail fairly quickly. The Application station has a 5K Scale up and I am currently testing 800 points. I setup a control module with 800 input parameters. 200 Floats, 200 INT, 200 UINT and 200 BOOL When enabling the 800 writes per second, i immediately started getting a scrolling list of failed writes. If i remove the 200 floats and 200 uints, the system recovers and i no longer have any fails. Does the 2000 writes per second come with an asterisk and it is data type dependent. Or maybe it is "Up to" 2000 writes per second. I'll do some research on the client connection duration. I am hesitant to use OPC Mirror since that is what we used several years ago and found it to be fraught with issues. Perhaps newer versions are hardened, but our original experience soured us on it.
In the communication settings for Kepware, I reduced the Max items per write from 512 to 400 and increased the write timeout from 1000ms to 2500ms.So far I am a little over 600K writes and 0 failures with all 800 points.
Going to ramp this up to 1600 and see how it does.
In reply to Invalid String:
In reply to Andre Dicaire:
In reply to Lun.Raznik:
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