dsc:| |-QueryInterface IID_IOPCBrowse: (FAILED, HRESULT=0x80004002 No such interface supported )

[gaetano_maron]

Hi, I'm moving my application from LV/DSC 8.5 to 8.6.1 and I'm getting the following problem.

I created an OPC Client I/O server to connect to the Eldridge Engineering Inc. Modbus - OPC server (http://www.opcsystems.com/modbus.htm). This server is DA 2.5 and supports Hierarchical browsing.  Looking to the client loggin file I found the following error:

| |-QueryInterface IID_IOPCBrowse: (FAILED, HRESULT=0x80004002 No such interface supported )

Apparently the client / server behaves properly when I read (by the "Distributed System Manager" tool) few items at time, but the client is disconnected when I ask to read few tens of items in one shot. There is no way to reconnect it, only way is to undeplpoy the client and deploy it again.  I don't know if the two problems are related each other. 

Any help is really welcome 🙂

cheers

gaetano maron

[matteobr]

Hi Gaetano,

when you used your application on 8.5 platform have you got any error or all works properly?

Thanks,

Matteo

[gaetano_maron]

Hi Matteo, with 8.5 the application was working fine.

gaetano

[matteobr]

Hi Gaetano,

I'm asking help in USA so it can take some days.

Hope that you can wait.

Cheers

Matteo

[gaetano_maron]

Dear Matteo,

thank you a lot for the help. Let me add some new things I discovered in the meantime. The error subject of this mail is probably due to an attempt of the client to estabilish a DA 3.0 connection, as this fails, the client goes to a browse interface compliant with DA 2.0 (QueryInterface IID_IOPCBrowseServerAddressSpace: (SUCCEEDED) ) and actually it succeeded.

Unfortunatley the final problem I got remains, so the origin of the problem is not this. Let me cut and paste by my previoisu mail the description of the problem .. 

Apparently the client / server behaves properly when I read (by the "Distributed System Manager" tool) few items at time, but the client is disconnected when I ask to read few tens of items in one shot. There is no way to reconnect it, only way is to undeplpoy the client and deploy it again.  

This is true both reading shared variables bound to the OPC client items that directly reading the items from the OPC client (always via the Distributed System Manager). If I work with the OPCQuick Client provided with the DSC distribution, this works fine.

I'm basically blocked by this behaviour. I have even problems to go back to 8.5, as 8.6.1 fixes several important bugs... so ... any hep really welcome 🙂

have a nice day

gaetano

[Chuck_81]

Hi Gaetano,

error 80004002 may require that you re-register the OPC server. See the following document for details:

Errors Connecting to OPC Server When Using DataSocket as an OPC Client in LabVIEW

Tools for Troubleshooting OPC Interface Problems

Furthermore, I have a couple of questions:

• Do you have both LV 8.5 and 8.6.1 installed on the same machine? Or they run on different PCs?
• I've browsed to the URL you forwarded http://www.opcsystems.com/modbus.htm It seems that Eldridge server also has a Modbus interface for communicating between applications.  As a possible workaround, have you tried to use a Modbus I/O server for interfacing with Eldridge SW? Here there are some tips about how doing this:

Using Modbus I/O Servers (DSC and RT Modules)

Troubleshooting Modbus I/O Servers (DSC Module)

Introduction to Modbus (see chapter "MODBUS I/O servers")

Hope this helps,

Best Regards,

Fabio

[gaetano_maron]

Hi Fabio, thank you for the hints. I'm going to try all of them. In the meantime I answer your question about LV. Yes, I have both LV 8.5 and 8.6.1 installed in the same machine.  Do you see problems in that ? 

cheers

gaetano