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12 Sep 2017 16:08 #5510 by support
Replied by support on topic Writing many tags
I apologize - I thought that I have replied, but apparently I did not.

With Isolated set to true, each such EasyDAClient will have its own OPC-DA connection to the server. Whether this will cause the server to use more communication channels to the PLC - I cannot answer - it is up to the server, so you need to ask the server vendor, or test it out. In general, OPC servers should expect multiple (many) connections to them, and for this reason, optimize the access to the device and not create separate connections in this way.

But, I do not see why you should need *many* objects with Isolated = true. If the Writes are causing the problem, you can use one 'Isolated' EasyDAClient for such Writes.

Regards

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12 Sep 2017 11:59 #5508 by I-Tecnology
Replied by I-Tecnology on topic Writing many tags
Any answer?

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04 Sep 2017 07:21 #5479 by I-Tecnology
Replied by I-Tecnology on topic Writing many tags
Please, explain me better the "isolated" property.
My PLC (Siemens S7-300) has a limited number of ethernet connection to use. When I configure an OPC device on my OPC server I use one channel of my PLC.
With the Isolated Property setted to True the number of comunication channel with PLC will increase? or only the number of channel with the OPC server will increase?
If I use many EasyDAClient object with Isolated=true, what kind of problem may I have? Problem with PLC o r problems due to the performance of PC?

The features of Isolated property are the same for OPC DA and OPC UA?

Best regards

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04 Sep 2017 06:44 #5478 by support
Replied by support on topic Writing many tags
Thank you.

By default, operations on the same target OPC server are serialized by QuickOPC, even if you invoke them from a different thread or on different EasyDAClient objects. In this respect, you are right, and this could be a reason why you are getting timeouts. BTW, 3 seconds are quite (maybe too) low.

If this kind of serialization is the issue, here is how to work around it: Set the Isolated property of the EasyDAClient ot 'true'. This causes it to use a separate connection to the target OPC server (separate from all other Isolated connections, and from the non-Isolated connection as well). Be careful - you can safely create quite a lot of EasyDAClient-s with Isolated = 'false', because they share the same target OPC server connection, but EACH EasyDAClient with Isolated set to 'true' will have its OWN connection. For this reason, you should think over the design carefully, and possibly share the same "isolated" EasyDAClient between the pieces of code/threads that actually benefit from using the same connection while keeping a separate EasyDAClient for other purposes.

Best regards

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03 Sep 2017 08:30 #5476 by I-Tecnology
Replied by I-Tecnology on topic Writing many tags
Attacched the error I get.
I think that the problem is that my writing operation is too long. So other reading or writing operation in other thread will have problem to comunicate with the PLC. I have timeouts in OPC client at 3s and I'm using asyncronuos mode. I'm using TopServer ver5.21 with default settings.
I think to divide the writing operation in many instruction of writemultiplevalues, but before to make this modify I want to know if there are some parameters to resolve this problem.
Best regards
Attachments:

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01 Sep 2017 08:52 #5471 by support
Replied by support on topic Writing many tags
Hello,

the default timeout on the client side is 1 minute. Are you saying that when doing this big write, other operations block for that long?

Or, are we talking about some timeout on the server or device side? Can you describe the symptoms more precisely, and send the actual error message and exception details?

Base on that I will then provide further advise.

Thank you

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31 Aug 2017 14:51 #5470 by I-Tecnology
Hallo,
I have a multithread application and many EasyDaClient objects. PLC is only one.
When I write a big number of tags(about 600bytes) with a writeMultipleValues operation using one of this objects, I have many timeout error messages from the other EasyDAClient objects.
Is there a parameter to make ths big write operation slowly?
Best regards

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