Labview to OPC connection: error 56 / Matrikon Explorer works

[wim_muller]

For weeks I am struggling with Labview to connect with an OPC server. The OPC server is installed on a remote pc en this pc is physically unaccessible.

Matrikon Explorer can connect to the OPC server and read tags, my Labview 2013/2014 program can browse the tag tree, but cannot connect to the OPC tag. This results in error 56 (a very general error). I have a test setup for my program (remote pc with Matrikon OPC server simulation). This runs perfect and my program is running fine in this test setup. I can create the error 56 in my test setup by setting timeout on a very small value, so I played around with the timeout values in the real system, but without any results.

I use the DataSocket Open and Datasocket Read blocks to connect and read the OPC values in my program. When connecting the OPC tag direct into a front panel indicator, the connection LED turns RED. When I move my mouse over it, the error: Access Denied is visible.

I tried to connect with OPC quick client, but this doesn't work either.

Anybody an idea?

[natasftw]

http://www.ni.com/white-paper/6417/en/

Is your OPC server on this list?  If the Quick Client can't see it, you're probably not going to be able to connect at all.

[wim_muller]

I'm not sure about the exact OPC server, but it is probably one of the Honeywell OPC servers in the list. Why is this important? OPC should be a standard and a OPC client should be able to connect to OPC server, no mather the origin of the OPC server. That's what standards are for?

With my Labview program and Quick Client I can browse the server, but when I want to connect to a tag, it is impossible.