When I disconnect my datasource to the OPC server (i.e. pull the network cable to the plc generating the data) Kepware says ‘Device no responding’. In OPC Quick Client, the Values are ‘Unknown’ and the Quality is ‘Bad’.
In FSQL frontend it says ‘E_Fail’ for value. Yet, FSQL is still writing values to the database every 2 seconds, as I had programmed. At first, they look like the last set of values recorded in the process. Then I stop the group and restart, and they are zeros.
This is not the behaviour I expected - if the OPC server loses data, I would have thought we would stop logging, through errors, something. Can someone help me - this is a dangerous situation because I am writing junk to the database, and in the future I may not know it. It’s probably a simle check box somewhere that I have overlooked.
The application is simple datalogging - read data from field device, put in database, and analyze in FPMI.