Thank you. Let me just verify it: With set up described in #2, even the application built with QuickOPC can start the AXS4ICCP service - but cannot truly access it (make operations on it). Is that correct?

Thank you.
1. Do you "pre-start" the service, or does is it started by first OPC client connected to it? If you don't start the service upfront, does connection attempt from your application at least start the service, or is the service still stopped? (Reason for this questions: There are two sets of permissions, Launch permissions and Access permissions. I am trying to determine which ones are causing the problem at first).
2. Have you tried to run the service under the same account as the Matrikon OPC server is running (or are you already doing it that way)? I understand that this may not be the best setup for production, and I also understand that other clients can connect to the service already, but I think it is a setup worth experimenting with, to gain a but more knowledge.
Kind regards,
ZZ

Hello.
Sometimes there are problems similar to yours, and they are difficult to resolve because we never managed to reproduce the same on our side.
This said, here are some questions and options:
- Can you please test whether BrowseLeaves, BrowseBranches or BrowseNodes call works? (the reason I am asking is because there some internal difference from how Reads and Writes work). Or, is there *anything* that works for that particular remote OPC server, or do all operations you have tried result in "Access denied"?
- What is the Authentication Level in DCOMCNFG properties for AXS4ICCP server (on the General tab)? If it is not Connect, have you tested with setting it to Connect?
- Have you truly compared the DCOM settings (in DCOMCNFG) for the Matrikon OPC server (that works) and AXS4ICCP (which doesn't) to every little detail? On the General tab, is the Authentication level the same? Is the information on Identity tab the same? Is the information on the Security tab the same, including the precise access control lists for any setting that is set to Custom?
- If the Matrikon OPC Server is on a different machine from where the AXS4ICCP server is, are the DCOM default on these two machines precisely the same? (right-click on the "My Computer" node in DCOMCNFG, select Properties). Is the information on the "Default Properties" tab same on both computers? Are the user accounts under the 4 options on the "COM Security" tab same on both computers?
Best regards,
Zbynek Zahradnik

Hello.
Your client code that uses QuickOPC is running in aWindows service, correct?
If so, what is the user account the client service is running under? Have you tried - just for the test - set the service to run under your account (the interactive account that you use when you run the UI-based clients that work...)? If switching the service account in this way helps, we will know for sure that you just need to tweak DCOM and the accounts/permissions again.
Zbynek Zahradnik

I'd like to clarify that responses from user 'kasssa' are welcome, but are not from OPC Labs technical support.
I will post our reply soon.
Zbynek Zahradnik