Velleman HAA54 - Manual (Page 3)

HAA54 GB 3
4. “Double-Twin Optics”-system : detection of changing polarity
HEAT
DETECTOR 2
HEAT
DETECTOR 1
CH 1
CH 2
CH 1
CH 2
CH 1
CH 2
CH 1
CH 2
Radio interference in "normal" mode
Only one channel is activated Both channels are activated
HEAT
DETECTOR 1
HEAT
DETECTOR 2
Changing polarity of the signal
caused by the intruder
ALARM NO ALARM