Can't configure OPC Client I/O Server

[jdrendon]

 Hi Bjorn

Did you fix this, I have the same problem. if you have some advice I will appreciate it.

Best Regards

Juan David

[bjla]

Hi Juan,

I have not got this to work. Currently I am working around the problem by using a Windows OPC Server for my PLC, but I am still interested in getting this problem resolved becuase I have to pay a license fee for the Windows OPC server, which I would not need if LabVIEW would allow me to browse to an IP address.

Since, I was time crunched on my project and needed to get something working ASAP I had not time to further investigate this issue, but now I should be having some extra time for this.

Any help from NI R&D on this issue is much appreciated.

Best regards,

Bjorn Larsson 

[Elizabeth_K.]

Bjorn,

Just to clarify, you are currently able to access the PLC tags via both the NI OPC Quick Client as well as another quick client (Softing). But you still get the "Error -2147467262 occurred at GetOPCServerList.vi" when trying to browse to the OPC via LabVIEW.

What version of LabVIEW are you using? Could you provide a little information on the PLC as well?

Regards,

Elizabeth K. 

National Instruments | Applications Engineer | www.ni.com/support 

[bjla]

Hi Elizabeth,

Yes, I still get the error.

I am using LabVIEW 2010 DS2 and DSC 2010.

The OPC server is an B&R Automation OPC server running on a B&R PLC. Here is a a short specification.

OPC Common 1.00
Specification for listing and connecting OPC servers

OPC DA (Data Access) 2.04
Specification for transfer of real-time values via OPC

OPC A/E (Alarms and Events) 1.03
Specification for transfer of alarms and events via OPC

The problem appears to be more related to how LabVIEW is resolving the host name when browsing to an OPC server on the network. Since, the OPC server is not on a Windows platform it will not identify itself over WINS. The only way to browse to the severis by manually entering the IP address of the server, which works well in the quick client, but not in LabVIEW.

Best regards,

Bjorn Larsson  

[Elizabeth_K.]

Bjorn,

Thank you for the detailed information. I have looked into our support materials, and have found one other issue regarding B&R PLCs. Do you happen to be using the x20? In that case, an OPC server running on the computer was used to connect to the PLC's OPC server. The computer's OPC server could then be accessed through LabVIEW. This may be the workaround you mentioned when you said that you were using a Windows OPC Server.

The problem may be related to resolving the host name, but more often then not this type of issue comes down to DCOM. You should ensure that the DCOM settings on the B&R PLC are configured correctly (this would have to be done through their support materials), and that the DCOM settings on the computer are correct for the type of communication you need to do.

Have you been able to communicate to the PLC in LabVIEW with DataSockets?

Connecting to OPC Systems Using LabVIEW (Windows Only)

Sharing Live Data Programmatically

Regards,

Elizabeth K. 

National Instruments | Applications Engineer | www.ni.com/support 

[bjla]

Hi Elizabeth,

I am using a X20 series controller and have setup the DCOM according to the documentation for the controller. Since, I could not get this to work I had to go with the Windows OPC option which works well, but comes with a license fee.

I agree that DCOM are most likely the problem, but I have spent 2 weeks trying different settings without any luck. However, as I wrote in earlier post; I can get DCOM to work for other applications and clients.

I will try the datasocket approach, however at this point I need to finish this project up using the Windows OPC and will not have time to do this for a couple of weeks. But, I am interested in getting this resolved for future projects so I will post something when I have tested datasockets.

Best regards,

Bjorn Larsson

[SnowForest]

Hi,

I think that I was have this same problem in one project. I solved it just by clicking ok to this error. It seems that NI OPC client (I/O server) can't communicate correctly with all OPC servers (even you have correct DCOM settings). In my case and maybe also in your case it is possible that OPC communication will be good even you are not able to browse servers. Try this:

1. Configure OPC client (write IP address + OPC server progID + click ok to all error pop-ups)

2. Create one test variable (I guess that you are not able to browse correct OPC items from OPC server so you need to write it directly variable binding field)

3. Test communication

This might be a workaround to your problem.

[phurtadoo]

Dear colleagues,

 

I have the same problem right now. I am trying to use the OPC to make a communication between a KUKA KRC1 robot (win95) and a PC working with WinXP.

I installed and tested the server in the robot. The network between the computers is fine. I also can connect to the server with the OPC Quick Client. I don’t know why, but the process to find the server takes several minutes in the OPC Quick Client. However, after the connection, the variables are monitored faster within the configured speed parameter.

Unfortunately, I can not configure the OPC Client I/O server of the LabVIEW 2010. I have the DCOM configured, as suggested here, but the communication still not working. I received the same error message every time that I tried:

 

"Unable to browse OPC Server from the selected machine.

Error -2147467262 occurred at GetOPCServerList.vi"

 

Firewall = OFF

DCOM = Wide open

opcproxy.dll = registered

 

Furtado

[TheGeeze]

Hi phurtadoo, 

Since you are using windows 95, I would like you to look at the following link:

Remote OPC Server on Windows 95/98/Me

Also, since you are on 95, I am concerned that your OPC server is using OPC DA 1.0, which is not compatible with DSC shared variable compatibility.  See this document.

Have you tried using Data Socket vis?

Ryan