What you mean visual? Or you talking about LED ,
As a house bashers I assume he's talking about when relays lock up without a diode
But your asking for visual, that would be a light emitting diode , unless your thinking it can be used in the same way
House bashing dot com
Excellent
You will also have to think about faults , with a fault he can't open the door at all, so you will still need some kind of override feature ,with the obvious secondary door access or manual shutter pull and so on
Basically possible to do with other problems to go with it
Competent diyers probably could struggle through it like texecom panels but will get stuck when you need to buy anything for it, pyronix readily available , visonic even more so since adt bought them and plenty of stock floating about don't you think? So easy for diyer
It's fun when hanging off the wall to do anything would be nice to have it hinged perhaps
Few I have seen all sound together never separated as you say
Model of alarm ? And pir ? Do a few posts so you can upload pictures
But could be you need master or engineer reset, or you dropped a spring , or tamper broken etc