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[Guest Tooey]

could somebody please explain what biscuits actually means? is it just to identify the detector or is it to encode the line? thanks

[ian.cant]

I know very little and have minimum experience with them but i believe the answer is both!

They allow you to run a sort of data line and attach the biscuits which have a different number ID which in turn allow an analogue device or sensor to be connected to it, as i understand them!

[Guest rjbsec]

Or then again there's Rich Tea with plain chocolate coating ... delicious!

[Guest Tooey]

biscuits are a term used to describe the id chip that is mounted in (should be in) the detector. There are 3 types of id biscuit, the original, a newer one marked with a letter before the number and the latest id+.

It stands for intelligent device and all of them obviously have an issue with me and i have to say the feeling is mutual. It great in theory. You can have upto 30 'biscuits' on a line connected to any device (dont extend the white wire whatever you do!) And it basically works like a decade counter

you have 3 pulses

2.85, 6.5 and 11.5v

2.85 is the basline, 6.5 the pulse and 11.5 the reset

if the line starts at 1 pulse of 6.5 v it then drops back to 2.85 and measures the current of the line. After the 1 pulse biscuit 1 knows the panel is talking to it and draws a different current depending on the state of the device (open or closed) obviously 0mA would be a tamper

it the stops drawing current and waits for 1 pulse again.

after the panel has pulsed once and easured the current it then pulses twice. Biscuit 2 now drwas current depandant upon contact status. then 3, 4 etc etc

after 30 pulses and biscuit 30 replies (or not if not connected) the line is taken upto 11.5v which tells all biscuits to reset their count and wait for their pulse again.

I beleive a whole line is scanned in 100ms so to old bs 300-800ms rule the biscuit must be in an open state for 3 successive scans.

Hope that answers your question

very much appreciated for the answers to my question