- 3 Nov 2006
- Reaction score
If you check the manual there is a jumper you can switch in the siren so that stray wireless signals will not cause the anti jamming circuit to set off the alarm.
EDIT Is not anti jamming, it is only jamming detection, an effective anti jamming function would require a change of radio frequency to use a clear un-jammed frequency
To disable the anti jamming circuit is the same as disabling the tamper circuit in the siren of a wired alarm system.
In a wireless system the siren has to have clear and reliable communication with the control panel in order that the control panel can command the siren to sound. If the communication channel is not clear and reliable then the control panel may not be able command the siren to alarm when an intrusion is detected.
In a wired system the comunication is by wires. If these are cut then the alarm will sound. In some wireless systems it is possible to "cut" the communications between control panel and siren by jamming the radio channel. When this happen it has to be bought to the attention of the user / owner of the property as the alarm is now not able to sound the alarm if an instrusion occurs.
If the wireless communication to the siren is being jammed then the communication from sensors to panel is also likely to be jammed and in some non compelled systems this will render the sensor in-effective.
Where the control panel function is part of the siren then the jamming detection function is essential.
( Compelled systems use two way communication between panel and sensors and if a sensor fails to reply to the sensor's requset for status then the system goes into alarm or tamper condition ).
With more and more equipment using the frequencies that many alarm systems use the incidents of jamming are going to increase.