Connectivity only with certain OPC clients

[jmedrano]

I have an OPC server running on a machine and I want to read data using a client that behaves as an OPC client on one side and does SQL query on the other. We have developed an application to do that and works fine when OPC client and server are on the same machine but we are having problems when running on different machines.

I guess both machines are properly configured as a 'normal' OPC client (QuickClient) can do both reads and writes successfully so it does not look like a typical problem with DCOM configuration, permission or firewalls.

The error I got is HR=0x80040202

Does anyone ever find such a problem that using different OPC clients one manage to communicate while the other does not?

Thank you very much for you support

[Support Team]

Typically wrong DCOM settings normally cause such issues, even though some applications may connect and other doesn't. You must imagine that there are:
1) global settings for the machine (all applications on the machine)
2) individual settings for each application
3) some applications may set their own security when started (CoInitializeSecurity)

Your error code "CO_E_FAILEDTOOPENTHREADTOKEN" is definately quite unusual. You may not have the correct proxy/stub installation. You should check for proper OPC redistributable package.

Best Regards
Support Team

[jmedrano]

The thing is that I do not have specific application configuration on the client side. Client machine has global settings.
Anyway, I have made a less safe configuration and it works, though I have not found out exactly the reason why.
I keep on trying different configurations to understand better the way everything works

Thank you very mucho