With one way kit the panel relies on the transmitter sending a signal at a fixed interval to know it's still there - to stop someone removing the
entire thing (without activating the tamper) and putting it out of range, for one thing.
This is not always that often, but the panel will be expecting to hear from the transmitter at some point. When it doesn't 'poll', an error should be
shown at the panel, on a scanny this would be a 'supervision' fault (although it can (foolishly) be disabled, on iOns at least).
This isn't to be confused with alarms (CC and tamper) or low battery signals.
Hope this helps! This is why 2 way or mesh kit is so much better.