Can't communicate with 2nd PLC

[PaulG.]

I'm trying to run RSlinx Classic OEM and two Allen Bradley PCLs in my LabVIEW 2010 app. I can see both PLCs and their tags in my I/O Server under my project, but the 2nd PLC shared variable values are not getting into my code. The shared variables are their and they are linked to the correct tag names but no values. The 1st PLC and associated tag/shared variable values have always worked fine. Suggestions? Thanks in advance.

[Ben]

Thoughts but no solutions.

Are you sure the affected SV have been deployed?

Did you try using a datasocket read to see if you can get the values from the I/O server?

Ben

[PaulG.]

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@Ben wrote:

Thoughts but no solutions.

Are you sure the affected SV have been deployed?

Did you try using a datasocket read to see if you can get the values from the I/O server?

Ben

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Yes and yes. All SV's are deployed with no errors. I'm getting a value from the 2nd PLC reading the tag URL with datasocket.

[Ben]

Double check everything with the second PLC and if nothing obvious, I would be dialing NI and logging a new service request.

That's all I can offer,

Ben

[PaulG. · Accepted solution]

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@Ben wrote:

Double check everything with the second PLC and if nothing obvious, I would be dialing NI and logging a new service request.

That's all I can offer,

Ben

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I called NI and they thought it was the ethernet divice driver to the PLC. But its the latest version. I tried setting up a 2nd remote I/O server for the 2nd PLC and that fixed it. It's confusing because all the tags show up in both I/O servers but I can only read the tags in the 1st PLC with the first server and the 2nd set of tags in the 2nd PLC in the 2nd server.

[Ben]

One I/O server per PLC?

That must be an issue with the server. I have done dozens of PLCs in the past with a single I/O server. That applies to different vendors as well.

What type of I/O server are you using (if you don't mind sharing) ?

I suspect you call this riddle solved but if not let me ask if you tried using the NI OPC server?

Thanks for the update!

When my phone rings, some day way in the future, I hope I can recall this story.

Ben

[PaulG.]

I'm using the RSLinx OPC server. I don't want to muck with it now trying something else. It's working.