Electrical circuit monitoring?

[MrEvoMan]

I'm looking for something that is able to determine if an electrical single is present or not through Linux perferrably.

The senerio I'm trying to figure out... I have a hydronic heating system and I want to be able to do some kind of reporting to which zones are requesting heat (I have 3 zones) and at which time of day, also comparitive to the temperature outside.

So, in the simplest broken down form, I just need a way to determine if the zone sensor is on, or if a signal has been sent to it. I know the voltage (24v) of the circuit and I have the temperature thing already solved.

Most of this is done in perl, I just don't have a way to get the information to the system that the zone has been tripped by the thermostat.

So does anyone know of a way to determine or watch a eletrical circuit or query if the circuit is powered in Linux?

[kingofkya]

the safest thing to do is use a rely on the 24v line to swithc a 3v logic from the parallel port. Or if you don't have a parallel port you can buy a ardueno for 30$ and do the same via usb.

[Solaris]

I monitor several Solar System controller readouts with small 2" b&w board cams and it works great. I can look at the exact same display, remotely 24/7.

If there is any way you can install an indicator such as an LED or something that changes and causes the picture to be different and detects motion, then it will record the event. You do not say if it is AC or DC voltage, but something can be done inexpensively I would imagine.

I tried hard to find an inexpensive way to simply monitor my system, and Zoneminder worked excellent for what I am doing.

Good Luck