Professional OPC
Development Tools

logos

Online Forums

Technical support is provided through Support Forums below. Anybody can view them; you need to Register/Login to our site (see links in upper right corner) in order to Post questions. You do not have to be a licensed user of our product.

Please read Rules for forum posts before reporting your issue or asking a question. OPC Labs team is actively monitoring the forums, and replies as soon as possible. Various technical information can also be found in our Knowledge Base. For your convenience, we have also assembled a Frequently Asked Questions page.

Do not use the Contact page for technical issues.

Meaning of error “Cannot connect Data Access client (timeout).” and “Cannot connect topic (timeout).”

More
29 Sep 2014 17:56 #2356 by support
The errors would be better listed in reverse order, as it is how they relate to the steps being taken internally.

1. “Cannot connect Data Access client (timeout).” (ErrorCode=-1073430527)

This covers the process that leads to connection to the “OPCServer” object inside the OPC Server. It includes (roughly) steps such as converting the ProgID to CLSID (locally or using remote OPCEnum), then calling CoCreateInstance to create the OPCServer object, obtaining interfaces from it, and hooking up (Advise) a connection point to it (for IOPCServerShutdown). If a serious error occurs during these steps, that particular error is returned. But if anything in this process simply takes too much time or blocks forever, and thus the whole process is not completed during the timeout period, the “Cannot connect Data Access client (timeout).” is returned.

2. “Cannot connect topic (timeout).” (ErrorCode=-1073430526)

This error can only happen if the ABOVE process succeeded, and it covers the process that leads from where the above part ended, up to the connection to the “OPCItem”. It includes (roughly) steps such as calling IOPCServer::AddGroup, obtaining variuos interfaces form the group, hooking up (Advise) a connection point for the actual data callbacks, and calling AddItems on the group, in order to actually add the items to the group. As with the above error, if a serious error occurs during these steps, that particular error is returned. But if anything in this process simply takes too much time or blocks forever, the “Cannot connect topic (timeout).” is returned.


Best regards

Please Log in or Create an account to join the conversation.

More
29 Sep 2014 17:54 #2355 by support
From: A.
Sent: Monday, September 29, 2014 4:58 PM

[...], the Error codes are “Cannot connect topic (timeout).” And “Cannot connect DataAccess client (timeout).” Could you provide a little more clarity on what the difference is between these two errors and what conditions you’ve experienced that might cause them?

A.&C.

Please Log in or Create an account to join the conversation.

Moderators: support
Time to create page: 0.044 seconds