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KepWareEX Connection & Read Response Times

13 Apr 2019 13:52 #7326 by support
QuickOPC disconnects automatically after some period of inactivity . The longer times you are observing are associated with (re)establishing the connection.
If this is a problem, you can either

- Prolong the "hold period" (defaults to 5000 milliseconds): .
- Create at least one subscription and keep it subscribed. It may be to a node that does not change; it can even be to a node that does even exist on the server.


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13 Apr 2019 12:55 #7324 by jestraub
We purchased and are running the latest version of QuickOPC 2018 in a UA COM capacity.

Our software is using the QuickOPC UA control from OPC Labs to access data on a KepServerEX 6 installation.

What we are experiencing is that our first connection/data read takes about 1.5 - 2 seconds, then subsequent reads take about 0.2 seconds. This happens as long as we read every few seconds (< 10 - 12). If we try to read every 30 seconds, we experience the lengthy connect/read times as the first time.

We did change from using a single read to multi-read call and that helped a lot but it is that initial connect/read when we want to get data at intervals greater than 10 – 12 seconds.

Is there anything we can do on the QuickOPC side to avoid the lengthy connect/read times on subsequent reads at longer than sub-ten second intervals?

Is there an active connection type of scenario being managed by KepServerEX that is allowing these fast subsequent reads? If so, is this configurable to allow the connection to remain open longer so we can do fast subsequent reads but a longer intervals?


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