Gruesste. Entschuldigen Sie mich sehr das ich auf Englisch Schreiben muss, weil mein Deutsch ganz schrecklich ist!

We are using a Merz OPC server talking to (3)Saia-Burgess PLCs. Our HMI is built in VB6.0 and uses an "opcdaauto.dll" we have from a free library source (Kepware ).
The system runs fine and the HMI updates for a day, sometimes more sometimes less, then the data stops updating though the server is still talking with the PLCs (I can see the polling using Ethereal). There are no errors logged as far as we see.
It appears that perhaps the data change bit no longer flags data change- though the data is changing. Restarting the HMI project restarts the comms and all is well.
I am presently testing comms with a commercial OPC client to see if it freezes as well, but I see this forum has a lot of experience with OPC and is more familiar with Merz (or Kontron) than here in the US.
If anyone has experience on Merz Server- OPC client issues- please respond.
Thanks in Advance.