DSC: Connection to 3rd party OPC Server

[sth]

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.

[Dave.C]

Hi sth,

I was able to find a KnowledgeBase article which should help to get a little more detail on why this is occurring.  You may need to enable Alarms and Events in the view menu of the Distributed System Manager. Let us know the additional details and any follow-up questions.

Thanks,

[sth]

I enabled alarming but still get the same error 0x8BBB0003.  That article seems to be from 2007.  As I said, I had this working in an older LV but 2012 is doing something different.

The error is:

"The Shared Variable bound to this Shared Variable process exists, but the Shared Variable does not. Ensure all Shared Variables are deployed and the URL of the variable is correct."

I am not sure what this means.  My shared variable is bound to a "project variable"  I created a bound variable that is supposed to source to my OPC server.

The network shared variable has a "networked published path" of "My Computer\NHML DCS Library.lvlib\NHMFL_DCS\FCS0101.LI200.PV"'

See the other thread (where I posted more detail) for a screenshot of my setup.

Thanks for the idea.

-sth

[sth]

You have got to be kidding me....   I find all sorts of restrictions that are nominal "bugs" or at least "unexpected behavior".  There is another thread where the description has to be filled in and the "alias" either unchecked or checked....  It was unclear, but I believe that unchecking it means that it is unconnected from the 

There is also the issue of the deadband being set to 0% to get updates?

Now I have to enable Alarms?  Ok, off to try this and other random property settings.  I wonder if it is worth creating a cryptographic brute force VI to set all possible property setting combinations to see what works!  🙂

It would have been nice if some of these were addressed in LV 12sp1 but that ship has left the dock....  Maybe LV 13?

[sth]

Dave,

Spent time reading documentation a second time...   

I think that my client SVE (Shared Variable Engine) is trying to log into the OPC Server with the default name "System".    My Distributed System Manager says that the variables are deployed but not connected.  The documentation shows how to set the OPC server login information for Win XP however I am on Win 7 which has a different way to set this up?

Any advice how this all works on Win 7 would be helpful.  XP is fairly ancient these days.

-sth

[Dave.C]

Hi sth,

Sounds like you've already been through this with a Service Request, but in case others happen upon this forum we used this KB to fix the issue:

http://digital.ni.com/public.nsf/allkb/9D1690C5B1CE1D25862572FA0053150D?OpenDocument

As you noted, the 2nd option, Changing the Log On Account for the SVE Service fixed the issue.

The instructions were a little vague but the same steps are involved for Windows 7 and XP. Note, when changing the Log On to administrator but you need to choose This account: and log in with an account with administrative access.

[sth · Accepted solution]

Dave,

My problem is very basic.  The instructions say go to the administator in the "control panels".  This doesn't exist in win 7.  I am stuck.  Here is the correct complete procedure as given by the very helpful Dylan Caswell.

Here are the instructions for Windows 7 (I will post this on the forum so others can see it or edit the KB if this works)

1. Press the Start Button and Type: Component Services
2. Click "Component Services" under Programs
3. In the Left Section of "Component Services" Expand: "Component Services>>Computers>>My Computer>>DCOM Config

4. Look for the name of your OPC Server (In this case yours should be along the lines of: "Yokogawa Exaopc Data Access Server"
4a (not sure if this is needed but I also repeated for the other server "Yokogawa Exaopc Data Access Server OPC Link1"
5. Right Click and select Properties of your OPC Server

6. Click the Identity Tab of the Properties Window
7. Select "The interactive user"
8. Select OK then restart the computer

This did not solve the problem, so I went on to the second step.

If this does not work, let's try the other method as described in the KB but for Windows 7:

1. Press the Start Button and Type: Services
2. Select "Services" under Programs
3. In the Right Portion of the Window, sort by name by clicking the "Name" column and then select: NI Variable Engine
4. Right Click NI Variable Engine and go to properties
5. Select Log On Tab and click This Account:
6. Select an account which is an administrator
7. Select OK and restart the computer.

There is a "right click" option to stop and start the service.  I did not reboot but merely stopped the service, counted to 5 and restarted the service.  

Immediately my running VI started showing valid numbers!!!