OT: VERY SIMPLE HOME NETWORK

[charles day]

Brian K. White wrote:
> 
>> The alarm is an automatic dial-out system, not a monitored system. I am
>> guessing the relay system is what makes it "non-filtered" in that the 
>> alarm wire with the relay open is the same as a jack with nothing 
>> plugged into it?
> 
> 
> That makes sense.
> 
> The part of regular phones and other devices that alters the 
> capacitance/impedence on the line is the part that listens for incoming 
> rings.
> Maybe the alarm system has no need to "answer" incoming calls and so can 
> be completely open-circuit whenever it's not making an outgoing call 
> itself.
> 

I think you are right.  It does nothing with the phone line unless it 
dials out.  The system is solid state, what's the term -- one pair of 
wires runs to an area where each of several sensors of various nature, 
knows its name or location and if triggered, tells the alarm computer 
which then dials and reports the particular violation(s) to the 
monitoring computer.  Closing the relay and dial out triggering is 
instant except for the permitted entrance doors with delay time to get 
to the control panel.

charles day