I am currently working on a customer project which consists of an Ignition Application (8.1) communicating with a machine PLC via OPC. A Kepware server is used to interface between Ignition and the PLC.
In the application there is a Gateway script which runs each second and updates a boolean opc tag (alternates True / False). This is processed by the PLC which in turn updates a second OPC Tag which can then be read in Ignition. The purpose is to verify that there is active communications from the gateway down to the plc and back up through kepware to the gateway.
However what I have noticed is that this works fine at first but if the Kepware server is restarted for any reason the write tag in the Ignition timer script stops working. The script will continue to try and write to this Tag but the value will not change. Also if I navigate to the tag in question in the Tag Browser the result is the same when i click on the tag to change it’s value it does not change.
There are no errors in the wrapper log when this occurs.
The situation can then be resolved by navigating to the gateway script disabling it, saving the project, re-enabling it and saving the project once again.
Any suggestions how to resolve this?