I suppose there may be some rules, and regulations and even logic, but it escapes me...
If I was making an alarm system* and someone tried to set the alarm and a fire escape was ajar, what would I do?
1. Beep in some cryptic way then set the alarm anyway so the bells go off and the idiot setting it (my son in this instance) realizes they have an issue.
2. Beep in some cryptic way then set the alarm ignoring the fire exit, so if someone does wander in the PIRs will pick them up and cause the alarm to go off.
3. Beep in some cryptic way and not set the bloody alarm at all.
To be honest I would probably do a bit of the first two. Set off the alarm but only long enough to make a point, and then go to a mode where set but ignoring the fire exit. Maybe if fire exit closes within a few minutes assume the problem was fixed and include it (and stop the bells).
What I would not do is option 3, not setting the alarm at all!
The alarm system in that case knows someone has tried setting the alarm and buggered off. It knows they have not canceled the setting and knows they have not gone back in the building. It basically knows they have not understood the cryptic beeps and have buggered off assuming all is well. So why on earth leave the building with an open door and alarm not set at all. That has to be the worst scenario of all.
As you can imagine, we have a nice high-end alarm system on the office and this is what the bloody thing does. Thankfuly I have extra monitoring on it and I get a text to say someone failed to set the alarm. So I had to go down there and sort it. Without that extra precaution we would have had an un-locked and un-alarmed office. At least the surveillance cameras are 24/7, but still!
* I say "if I was making an alarm system". Obviously I did, 20 years ago. I made a door entry and alarm system for my house in Newcastle. It was designed and built by hand using leaded components, wire wrap sockets and a bare breadboard. It used a lot of wire wrap. 6502 based. The door entry was mag card (credit card) using a head from an old cassette tape player. Obviously all my own software - I even wrote my own assembler. It worked well for many years until I re-made it from a PIC 16C84. Sadly, these days, double glazed uPVC doors mean I have to use a key at home.
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