Frontend - backend gateway comms loss

I have a frontend gateway that houses the perspective part of the project. The backend gateway handles the connections to the database and plcs. I want to monitor if the frontend gateway connection is lost to the backend. What is the best way to monitor? I was hoping to use some sort of built in tag and to say something like if that tag indicates a loss of comms for x seconds that trigger a warning bit or alarm bit.

Under the system tags, the under gateway network shows boolean tags on whether the connection is there or not.