Common alarm mode of perimeter alarm system
I. alarm mode of pulse electronic fence
A. cut off the line in case of open circuit (the receiving port cannot receive the pulse signal);
B. short circuit (the resistance between two transmitting terminals is too small) the adjacent two wires are short circuited.
II. Alarm mode of tension electronic fence
Climbing, pulling, pressing and cutting; the spring senses the change of tension and generates an alarm.
III. vibration optical fiber alarm mode
The interference of digging, touching, knocking and so on forms the waveform change and generates an alarm.
IV. underground leakage alarm mode
It can detect the conductivity, volume and moving speed of the intruded moving target. People or cars will be detected through the electromagnetic field, while small animals or birds will not cause false alarm.
V. infrared counter fire alarm mode
When an object crosses its detection area, it blocks the infrared beam and triggers an alarm.