Everybody knows that wireless alarm systems are unreliable during Radio Frequency Interference (RFI) because the transmission path of signals between sensors and wireless receiver is muzzled by an external transmitter causing RFI. Wireless is unreliable during RFI, and there are a tremendous number of sources who generate it, theyre number increases day by day.. YOU WILL NOT BE WARNED THAT YOUR WIRELESS SYSTEM is DEAD.
Is RFI detected? Let's see what "so called" professionals say about the lack of the sensor data reception detection circuit.
All wireless alarm systems have tamper and battery low detection. The presence of an extra bit(s) in the coded sensor transmitted signal stream allow the control panel to identify the occurrence of tamper or battery low. Some of the so called pro's attempt to convince you and say that this is also useable and effective for RFI detection.. Everybody knows that no valid signal reaches the wireless receiver during RFI.. how can that work when transmitted signal and there detection just fail because RFI jeopardize the RF loop signal validity??? Forget it, its sellers talk.
In some new and recent systems each sensor transmit on a regular basis to the panel an "I'm here" signal. The panel takes note if all are received correctly within a certain timespan. Some systems have a signal strength indication to. This design feature is used to check validity of the sensor reception signal at installation.It allow to see if all sensors are located at a receiver signal reachable place.
Note: If this feature is always left ON, it detects continuously sensor transmission failures and sensor position problems caused after installation due to the displacement of conductive objects (statues, car and other metal objects). The displacements of a conductive object alter the RF signal path by masking completely or partially (attenuation) the transmitted signal to the receiver, the signal decoding of the system fails.
Most of the time the installers "disable and put OFF this feature" because it don't identify typically RFI from sensor "transmission path" failure, both occult signal reception validity. There is a way around the problem, metal object obstruction is usually for a rather relative long timespan before it is removed (statue, car), by tuning up the time delay the system can warn lack of sensor signal and +/- avoid false alarms. This works and is effective for long (hours) time delays before warning occur, unusable to detect intruder generated RFI.
Until now, according to pro's, no interference warning has been received at central stations during 20+ years.. Conclude yourself of the efficiency of that RFI detection...
Why doesn't the most recent developed systems not detect typically interference situation? Because there are several interference sources, situations, impossible to identify them (see diversity of sources i described) and during that time, the wireless systems are muzzled, dead.
Conclusion: Assume that there is some kind of detection that really works(?), it don't solve the muzzling and intruder "detection" during interferences. You think there are systems who detect RFI, well try it out with a RFI generating transmitter preferably in a crowded wireless users area at night and see how many nightmares it will cause, police adventures, and more.. Good luck