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Writing an item value (byte) takes different Long times???

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01 Mar 2016 10:11 #3893 by support
This can be caused by the server, or by the client. Let's start with the client, which is what we can influence. QuickOPC maintains OPC connections automatically, and creating a connection takes some time. It is therefore possible that the shorter times you are seeing are in situations where the connection already exists, while the longer times are when the connection needs to be set up first.

Default hold periods are "relatively" short (max 30 seconds). If you do your Write-s less frequently, the connection would be closed, and then needs to be reestablished.

QuickOPC keeps a connection open 1) for a configurable time period after operations like Read or Write, and 2) while any subscription exists.

You can use e.g.
easyDAclient = new EasyDAClient();
 easyDAclient.InstanceParameters.HoldPeriods.TopicRead = 5*60*1000;
 easyDAclient.InstanceParameters.HoldPeriods.TopicWrite = 5*60*1000;

- in this case, to extend the hold periods to 5 minutes, or any other time periods that suits your needs. If you increase the hold periods but still your 2nd and subsequent Write-s take sometimes longer, the problem would rather be on the server side.



Best regards

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29 Feb 2016 12:50 #3891 by tmouslih
Hello,

Writing an item value (byte) takes different Long times???

_easyDaClient.WriteItemValue (_TCPServerAdress, _ServerClass, tagName, value);

The execution time of this call takes between 50ms or longer up to 800ms.


I would be very grateful if you can answer me the question. What is wrong?
How should I do it, so that the execution time is fast and remains constant?

Thank you very much.

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