Re: Wired/Wireless Alarm Systems



"James Dabbs" Wrote:-

I'm looking for the communication protocol used between alarm central
stations and their keypads. Are these available, and if so, where would I
go to look?

Also, is information available on "wireless" alarm systems? E.g., how
wireless door alarms, PIRs, etc. transmit data to the central receiver.

Any information would be helpful, specifications, licensing info, etc. I
want to modify a product to communicate with these devices.

You will not find the keypad to panel protocol for any professional
commercial alarm system and I doubt any other either. If the protocol was
freely available you would be able to create a keystroke logger by attaching
a dodgy device to the data bus, log the access keys and hence be able to
disarm and gain free access to the property.

You could of course scope the bus and see if a valid fixed baud rate is
apparent and attempt to go from there. Depending on system complexity this
could be near impossible and at least very time consuming.

As to how wireless detectors etc. communicate to the alarm panel this may or
mat not be available, but you may still hit a brick wall (depending on the
grade of system you use) in that all communication will be encrypted in some
way to stop record & playback and brute force attacks on the system.

I have never seen (even really cheap do-it-your-self systems) wireless
systems without encryption & rolling code employed.

Jim



.