Hello,
this is a static property of the EasyDAClass. You should be able to put the line I have recommended before the instantiation of the EasyDAClient; it will then have influence on all 'new' EasyDAClient objects created.

Hello,
Thank you for the problem capture. We can now tell that the error comes from the call to the OPC Server. Specifically, an error code E_UNEXPECTED is returned by IConnectionPoint::Advise method for the IOPCDataCallback connection point on the OPCGroup object of the target OPC server. Contrary to what it initially looked like, it is not *directly* an error code generated inside the client component.

Without having ability to reproduce it here, it is difficult to say what is causing it. In one sense, we could tell that “it is not our fault”, because the code is coming from the OPC server (or the proxy), and the parameters passed to it are correct. We would even be able to put the OPC Analyzer in between, capture the communication, and point at the problematic error code returned to us.
But because there are other OPC clients that work well from the same computer (at least, the COM component of ours), it would also be possible that there is something indirectly related that causes the problem. And, I am suspect of the COM/DCOM configuration again, because it is such a common source of issues. Furthermore, the low-level connection and OPC handling code is *identical* in the -COM and .NET products.

Some COM/DCOM settings are made inside our component, and some are left to the standard system configuration means (DCOMCNFG tool). For start, I suggest to experiment with following statement (put before any other OPC code) to see if they help:


EasyDAClient.ClientParameters.TurnOffActivationSecurity = true/false;


Also, can you please tell me some more information - below?

Is the OPC server located on the same machine, or remote?
If remote, what DCOM configuration settings have you made, if any?
Which OPC server are you connecting to?


I understand that you are in product selection phase, and you just expect a working solution, but due to the nature of the issue, we cannot provide it in “one easy step”. Thank you for understanding.

Hello,
thank you for waiting.
Attached here is a special build of the component assemblies. It is modified to (hopefully) identify the place where this particular error code is coming from. Can you please rebuild a simple Windows Forms application (it could be the Demo app) with these assemblies, and reproduce the steps that cause the error. What should happen is that a series of message boxes will pop up, similar to the one below, but with different data:
Untitled.png
What we need to know is the "File" and "Line" from these message boxes - at least from the first message box, and depending on its contents, possibly from several subsequent ones.
Many thanks
Zbynek Zahradnik
Assemblies.zip

Thank you. If there is no Source info, it is likely that the error comes from the client side, and therefore we will not need the OPC Analyzer for start. Instead, a special (debug) version of the component can be deployed, and it will hopefully give us more information.
Due to holiday time here, can you wait for approx. 10 days before this can be made available to you?

Thank you, and best regards