Professional OPC
Development Tools

logos

OPC XML-DA. Error: The item value does not specify a timestamp.

More
15 Oct 2019 09:12 #7827 by support
Hello.

Please download and rebuild with the latest QuickOPC 2019.1, build 422.1 or later, as on our Web page and NuGet.
We have made the code more forgiving in this respect. Missing timestamp in the case you have described should no longer cause an exception.

Best regards

Please Log in or Create an account to join the conversation.

More
03 Oct 2019 07:59 #7787 by Andriy
Hello,

I agree, it's a mess. Therefore, I will create separate topics for issues #2 and #3.

I was able to reproduce an error: "The item value does not specify a timestamp."
QualityField="badWaitingForInitialData"


QualityField="good"
Attachments:

Please Log in or Create an account to join the conversation.

More
02 Oct 2019 15:35 #7786 by support
Hello.

In the future, please put each issue into its separate forum thread. It is really important. We now have 3 issues here, under an incorrect title. It is a mess. . To sum it up, they are:
1. OPC XML-DA. Error: The item value does not specify a timestamp.
2. Number of open sockets.
3. commFault in getStatus call.

If they are related, links can be used to provide the relationship.

Regarding the number of sockets: Does it grow without a limit, or does it stabilize at or around certain number?

Best regards

Please Log in or Create an account to join the conversation.

More
02 Oct 2019 14:52 #7785 by Andriy
Hello,

Vendor info:
Arosii OPC XML-DA framework, Nordex RFC OPC XML-DA Gateway

I cant reproduce the issue "The item value from OPC NET API (Data Access) does not specify a timestamp." anymore.
It happened with All items but only once when "ItemChanged" notification was triggered first time.

Regarding the sockets. In my case this is a problem. It causes OPC server to stop working after a while
I have to use polling instead of subscription to workaround this problem.

But there is another problem.
My opc client is stuck in reconnecting to OPC server. I run Wireshark to trace communication and find that OPC server returns "commFault" state on GetStatus call.
Can I can disable "GetStatus" method call or inject my own handler of "GetStatus" response?
You informed me earlier that I couldn't disable "ServerStatusCheckPeriod" for OPC-XML protocol. Is it correct?

By the way, dOPC client just ignores opc server state. So, it does not have such problem and opens only 1 socket in subscription communication mode.

Regards

Please Log in or Create an account to join the conversation.

More
01 Oct 2019 06:47 #7781 by support
Hello.

In question 2 , I wanted to know not just the technology (OPC XML-DA), but also the vendor/model of the server, if possible, please.

Additional question: Does this, in some scenario, happen with ALL items and consistently - that is, you cannot actually get any data from the server using subscriptions? Or only for some times? Or does it work for some time and then it starts issuing these errors? Or is it kind of random?

Regarding the sockets: The nature of OPC XML-DA subscription is in separate HTTP requests being issued over time, and each of them may have its own connection (= open socket). They should, however, be closing after some time. That is, if the number of open sockets does not grow "over all limits", I do not see it as a problem.

Regards

Please Log in or Create an account to join the conversation.

More
30 Sep 2019 14:42 #7774 by Andriy
Hello,

1. Yes
2. OPC XML-DA
3. I don't know. It is reproduced only when subscription is used.
4. I will try to do it

I've noticed another thing. ConnectivityExplorer opens a lot of tcp sockets when subscribtion mode is used. The OPC server is the same - OPC XML DA. Why?
Attachments:

Please Log in or Create an account to join the conversation.

More
30 Sep 2019 12:18 #7773 by support
Hello.

1. Is this an exception contained within the event argument of the DataChange notification:
2. Which target OPC server is this with?>
3. Is there a way for us to reproduce it?
4. Can you capture the network communication?

Best regards

Please Log in or Create an account to join the conversation.

More
30 Sep 2019 11:42 #7772 by Andriy
Hello,

I get an error from OPC XML-DA server after subscribing to opc items: "The item value from OPC NET API (Data Access) does not specify a timestamp."
Can you explain what is wrong?
Do you know to to fix it?

Regards

Please Log in or Create an account to join the conversation.

Moderators: support
Time to create page: 0.273 seconds

      

 Recommend this on Google