Security alarm wiring to garage

Alarm systems have a bunch of standardised protocols (think zigbee-like things) and the transition to IP has been a difficult one.

If you think of an older pabx where they were "ip capable" but all that allowed you to do was go to a website and change the day/night mode redirections and basic config - no voip stuff.

*most* major brands of alarm system (paradox, dcs etc) are still at a similar stage to that.
Some have a ip capable interface where you can run an app on your ipad, or website, and login to view things like zones etc. Its all still very basic.

The biggest thing though is you have IP Diallers now.
These interface using the protocol that connects the panel to the modem/dialer.
The IP dialler just converts the commands and sends it over the internet - used mostly for monitoring companies.

I would love a proper home automation system - with a master controller which was IP capable for remote access, and then other devices around the house that run on it.
I dont think the devices/sensors/switches/locks etc should speak IP because that is not reliable enough. But if they used a standardised protocol and were compatible with cat5 cable, and you could get expander units that had maybe 30 ports, and a single cat5 backhaul to the master controller then that would be good.
So the theory would be that everything works on rules. In the programming interface, you could create a home alarm system by following a wizard that creates a set of rules.
At home we do this with our current alarm system though its very restricted - when the gate is opened, the light outside automatically switches on, as well as the light in our lounge.

I would love to do more things - so adding a "button" which when pushed, a rule was triggered, and relay 5 on expander board 2 was closed which happened to be wired up to the hallway light - effectively creating a light switch by using a relay module and a wall button module.

Or when a remote button is pressed in the car outside, a set of rules will open the gate, disarm the alarm subset of rules, open the garage door and switch on the lights in the yard and lounge (if it was after 6pm)

I just checked with chris on his comments about the cat5.
We rambled a bit but this is how I understand it:
Its not the fact that a cat5 cable is capable of carrying milliamps.
Some panels have say 10 zones - or 10 ports for sensors.
However you can "double up" on some models and have 20 zones from those 10 ports.

Two PIR sensors can be wired up in parallel and a resistor put inline/series into one of the sensors.
If one PIR sensor is triggered, it can close the loop and tell the alarm panel zone 1 is going off because there are almost 0 ohms of resistance.
If the second PIR sensor is triggered, it will close the loop, but the inline resistor creates a measurable amount of resistance across the contacts and so the system knows this is zone 11 going off.
By using a cable with a high resistance or lower AWG, enough length may create the same amount of resistance required to imitate an inline resistor with the zone 1 sensor, making the panel think zone 11 is being triggered.
This isnt so much a problem with home or basic alarm systems, but commercial ones with different codes that disarm different zones (staff access rights) etc can have some very complex designs, which involve such trickery.

mdf

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nickb800

raytaylor