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ReadMultipleItems

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23 Feb 2021 15:29 #9472 by support
Replied by support on topic ReadMultipleItems
Thank you for update. I am glad that it works.

Still I am unclear on what caused the difference between Conn.Explorer and the Python program, but hopefully hat doe snot matter any longer.

Best regards

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23 Feb 2021 14:02 #9471 by Sakai
Replied by Sakai on topic ReadMultipleItems
Hi,

With the code didnt work.
But with your explanation i review some configurations, and see that the firewall was on.
I turned off and its working now.

Thank you for the Support !
The following user(s) said Thank You: support

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23 Feb 2021 10:38 #9470 by support
Replied by support on topic ReadMultipleItems
Hello,

I do not see you doing anything wrong. Sometimes, there are problems with callbacks (DCOM) that manifest themselves like this, but it is weird that it works from Connectivity Explorer but not from Python.

Anyway, to rule this out, can you please set one property right after creating the EasyDAClient instance? Have not tested the syntax in Python, but it should be something like this:

client.InstanceParameters.Mode.AllowAsynchronousMethod = False
Best regards

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22 Feb 2021 12:42 #9465 by Sakai
Replied by Sakai on topic ReadMultipleItems
Hi Support Team.

1. Both pictures are from the same machine. So yes , the Connectivity Explorer is working fine, but not with python.
2. With the Explorer, i can read and browse with no problem. But with python i receive this error of ReadMultipleItems

3. Yes both methods are trying to connect to the same Server.
4. I also tried with 'VMES' instead of the IP, but with the same error.

5. Yes, for both computers i'm using the administrator user, with the same pw, to have a easy access to them.
I dont know if this can be useful but they are 2 different computers, one with win10 and other one is a legacy system with windows XP
The XP Server is with a Siemens PCS7 and we connect trough the WinCC, the other one is the Win10 with OPC lab and python Installed
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22 Feb 2021 11:54 #9464 by support
Replied by support on topic ReadMultipleItems
Hello,
I have some additional questions:

1. Are both pictures from the same machine? That is, the Connectivity Explorer works, but the Python program doesn't?
2. Or, is the problem perhaps related just to reading, and not to browsing? Have you tried to Read in the Connectivity Explorer, and what were the results?
3. Are both pictures intended to connect to the same target server?
4. If so, why are you using IP address in your Python program (Note: it is OK to use it, as long it is the correct one). Have you tried the same as Connectivity Explorer is using, that is, the computer name "VMES", in your Python program?
5. Is your Python program running under a normal user account, e.g. a console application that you start yourself, or is it hosted in some other runtime environment, and perhaps under a different user account?

To your question: You can pass in either ProgID, or CLSID in curly brackets. Normally one would use ProgID. But CLSID has the advantage that it does not require additional lookup step (using OpcEnum service or registry browsing), and might therefore work in some more cases.

Kind regards

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20 Feb 2021 01:28 #9463 by Sakai
ReadMultipleItems was created by Sakai
Hi , i did the example in python to test a OPC connection with the KitServer, and everthing went fine.
But when i was trying to connect with another OPC server i receive a timeout and then, i get the ReadmultipleItems error.
I dont know if i 'm missing any new configuration
But i'm trying the command value =client.ReadItemValue('192.168.0.126 ', 'OPCServer.WinCC.1','AIR/I.U')
I dont know if i need to pass the CLSID, once i have the tree as follow in attachements

Can you guys Help me ?

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