DataSocket Select URL.vi

[RasmusVistisen]

I have an application where I would like to give the user the option to select multiple OPC tags. I am using the DataSocket Select URL.vi

This VI will by default only allow the user to select one URL, but I would like to be able to select a URL with subgroups and multiple tags.                                                                             

Anyone knows a workaround using this VI or another way to select multiple OPC tags?

[spacedan]

Hi, 

It looks like the following example could get you started:

https://forums.ni.com/t5/Example-Programs/Programmatically-Select-URL-and-Read-Multiple-DataSockets/...

Does this help?

[RasmusVistisen]

Hi Daniel,

thanks for the reply, but it seems this example requires the user to select each tag one by one. What we would like to achieve is that the user can just select a path and then the program will be able to detect the tags in the path.

[spacedan]

Hi again Rasmus,

I see. I am not that well versed in this particular subject, but it looks like you might be interested in "Getting the OPC Server Tag List" in the following white paper: http://www.ni.com/example/31341/en/

An example built on this can be found on:

https://forums.ni.com/t5/LabVIEW/OPC-Can-I-read-in-a-list-of-all-available-tag-names/m-p/1455454#M55...

You would then dynamically iterate through the tag list as an input to DS open. 

Let me know if this helps!

[RasmusVistisen]

Thanks Daniel,

It seems like it could be a solution, but it looks like it requires the DSC module to work. Then development license fee would be ok, but we have 50-100 distributions of our application, so the runtime license fee makes this a less attractive solution.

[spacedan]

Hi Rasmus,

Why do you think it requires the DSC module? I can run the VI (Get Tag List) with the DSC module deactivated.

[RasmusVistisen]

Hi Daniel,

It says in the white paper:

Discovering and Selecting the Machine

The discovery and selection of a networked machine is accomplished using a VI named opc_BrowseMachine.  This VI is installed with the LabVIEW DSC Module and is therefore locked (password protected).  It is not on the functions palette and therefore could change without notice when upgrading LabVIEW.

When I run the example on my laptop (without DSC) it does not find the NI demo opc, but it does with the datasocket select URL.vi, see pictures.

[spacedan]

Hi Rasmus,

I see. I have not been able to come up with any clever way of doing it without the DSC module. Have you made any progress?

In the meanwhile, I have posted the issue internally, and hopefully, someone more experienced can help us out. Will keep you posted.

[RasmusVistisen]

Hi Daniel,

Ok thanks, looking forward to hear if they have some input.

I have not been able to come up with a solution. I'm looking at 3rd party solutions, but haven't found one yet that will integrate easily in VUDAQ.

[spacedan]

Hi again Rasmus,

How is it going for you? I am afraid I have not heard back about any other solutions. It looks like the DSC module is required, at least according to the white paper. Note, however, that although I could run the Get Tag List VI, I did not see the NI demo OPC either.