DSC: Connect to OPC Server Problem

[sth]

(Sorry about the previous incomplete post, my attempt to edit it timed out)

I had this working with LabVIEW 2011 and Win XP....  After update I can't get it working....   Now with LabVIEW 2012 and Win 7, the server is also now upgraded to a Win 7 system.

I am trying to read variables from a commercial Yokogawa OPC Server.  I can connect to the server.  I can see the variables and create a bound shared variable.  But when I access the variable it fails.  Here is the simple test project and code with error.  I create an "IO server" as NHMFL_DCS and select the correct node and library.  I then create the shared variable LI200_PV by selecting the correct tag in the list from the sever (the server  sends the tag list correctly).  But using the shared variable seems to fail.

Use fo the "OPC Quick Client" works just fine and I can get the OPC Server tags just fine.

I am obviously missing an important step.   Any OPC Server experts out there?

-Scott

[Aix-La-Chapelle]

Hi sth,

Have you seen this guide?  http://www.ni.com/white-paper/7450/en

If so, by following those steps are you still receiving the error you describe?

The error -1960679037 is related to an error during initialization of the variable as seen in this KB: http://digital.ni.com/public.nsf/allkb/B9366256C53D95CA8625725A007C0287

One thing we can check is to follow this KB: http://digital.ni.com/public.nsf/allkb/9D1690C5B1CE1D25862572FA0053150D?OpenDocument

As the DCOM settings for your particular OPC server may be blocking LabVIEW access to the tags. 

[sth]

Yes, I saw the guide that is how I originally got it working under Win XP.  The guides for fixing problems all reference Win XP for setting DCOM values.

I got some help from an AE (Dylan) who walked me through how to do this under Win 7.  As a non-Win kind of guy it was not obvious how to do the DCOM settings under 7 that were discussed in the XP.  Hopefully Dylan will post those directions here.  The main problem is that those administrative services are not available through the control panels any more and one needs to know the arcane secret configuration system to find the correct gui for the DCOM settings.

[sth]

See solution in other thread.  Applogize for the multiple threads