In my project, PLC(VPB40) plays role as server, it opens the port and listen to connection request from IPC.
Normally, both sides are working well. However, there is QCD error if production line stops due to part missing.
It means that connection between IPC and PLC is established, command from IPC to PLC is correct and response from PLC to IPC is also correct. In this case, if production line stops becase part missing and connection between IPC and PLC kept. After a period of time, customer told me around of 2-3 hours, there will pop up QCD error on PLC HMI.
Since i am not so clear about QCD mechanism. Anyone could help explain it and give me some advice about this error.
If you have access to BCI's network share, then you can find some documentation on QCD in the \Automation\ControlClassic\_GeneralInformation\Objects (FB's)\Internal Functions\QCD\ folder.
Your error has something to do with the TcpIpBase lib. (QCD Layer1=7, Layer2=3, check the details tab of the properties of the Std\PLC\Qcd\Qcd_L3_007_003.exe file)
Maybe in some cases some data is missing?
BBacskay is correct, this is related to the TcpIpBase Lib.
Error 9517 means that the mailbox (receive queue) to Qcd_L3_007_003.exe is full.
This might happen if the exe has crashed or is blocked.
Please check if there are any errors related to the tcp/ip library in the eventlog.
You could also check if all Qcd_L3_007_003.exe instances are still running.