When Home Guard is not armed, pressing the arm button arms the system. Pressing it again disarms the system.

HomeGuardFixtures.CheckFrontPanel
armed	visual alarm	siren	display
off	off	off	READY

HomeGuardFixtures.Control

press arm button

HomeGuardFixtures.CheckFrontPanel
armed	visual alarm	siren	display
on	off	off	ARMED

HomeGuardFixtures.Control

press arm button

HomeGuardFixtures.CheckFrontPanel
armed	visual alarm	siren	display
off	off	off	READY