OPC Server Remote Connection LabVIEW 8

[m_adriano]

Hi

Currently I am trying to access a VI with a Shared Variable from a remote computer using an OPC Client. I haven´t succeed on this becasue I cannot find the OPC Server on the Host Computer.

Here is what I am using:

Host Computer:

Windows XP SP2

NI Developer Suite November 2005

LabVIEW 8 with DSC Module.

Remote Computer: The same as above.

Here´s what I have done.

I created a new project with a library that included a Network Published Shared Variable. The VI is quite simple it just generates a number that is written to the Shared Variable. Once the VI was running I opened the Server Explorer on the host computer, browsed My PC and connected to the server Variable.Engine in which I was able to see my shared variable. Then on the Remote Computer I opened the Server Explorer and browsed on my Network Places and when I tried to access the Host Computer I got the following error: "Unable to connect to \\HOST! Make sure that this computer is on the network, has remote administration enabled, and that both computers are running the remote registry service"

I have tried by using the Matrikon OPC Server Explorer and I got the same results. I read many documents that refer tis problem as a DCOM setting because of the firewall fo XP SP2.

Here´s a list of the NI documents I reviewed.

How Can I set up LabVIEW, LabVIEW DSC, and Lookout to work with the windoes XP firewall

URL: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000YIKqCAO&l=en-US

Setting Proper Access for Remote OPC Server When Using National Instruments OPC Clients

URL: http://digital.ni.com/public.nsf/allkb/5C8A90CD57B279F286256C2C006F1EB4

I never got the results I expected. Then I tried the Matrikon OPC Simulation Server and the Matrikon OPC Server Explorer(Client) and I Succesfully connected between Matrikon servers and clients.

My project is based in accesing the LabVIEW OPC server with a generic OPC client but I cannot get the client to connect to the server.

I will apreciate some advice on this issue.

Marcos

[Khalid]

Have you applied the DSC 8.0 updates?  There's an OPC update in there.   Though the fix appears to be for an issue with DSC's OPC Client browsing, it still might be worth it. 

Read me:

https://download.ni.com/support/labview/labviewdsc/updates/8.0/readme_DSC_8_0_1.html

Updates:

https://download.ni.com/#support/labview/labviewdsc/updates/

Regards,

-Khalid

PS:  Please backup, etc. before applying the update. 

[Doug M]

Marcos,
If you are using two instances of LabVIEW 8, I would first take the OPC part out and just try viewing Shared Variables on the remote computer.  This needs to work.  One document to check is the following KB: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P6vdSAC&l=en-US. I would also make sure the opcenum.exe service is running on both machines. 

Once browsing to Shared Variables works, you can test the OPC aspect of the Shared Variable Engine.  Server Explorer is an older OPC 2 client, but should work in most cases to browse to OPC Servers -- you'll need to make sure the registry settings on the host computer are set up correctly as per the KB you mentioned, and also make sure to connect to the OPC Server, add a group, and add items manually from within Server Explorer, rather than using the Wizard.

[m_adriano]

Thanks on the suggestions.

I already manage to read the shared variable value on the remote machine using both Server Explorer and Matrikon OPC Explorer. I accomplished this doing the following

On the remote computer I browsed the localhost tree to the "National Instruments.LookoutOPCServer1" Then I connected that server and added a group "x" in which I also added an Item. In the Item definition window I was able to see the localhost tree and the network tree in which I found the Remote Server with the Shared Variable that I was looking for. After adding this to the group I was able to read the values across the network. I tried this in different remote computers and worked fine. I also tried with generic OPC clients and also worked fine.

So now I am a little confused because I am accessing remote servers by browsing in my local LookOutOPCServer. Isn´t supposed to have to access from the "My Network Places" tree on the Server Explorer?

Best.

Marcos

[Khalid]

Marcos,

It appears you're using the local OPC Server for the shared variables and through it getting to the remote items.  So, you're not really doing remote OPC here.  And this will NOT work with a generic OPC Client on a machine which does NOT have LabVIEW-DSC installed.

Regards,

-Khalid