Well, I did not get a ton of replies to my inquiry about the Versus
cellular backup units. So, now that I have had a chance to play with
one I will post what I learned in case it is of interest to anyone
down the road.
There are two main parts to this unit: the cellular transceiver and
the alarm interface board.
The cellular transceiver looks to be a 'standard' type unit with a
flip up flexible low gain antenna, port for 12v in, handset, and
accessory. It also has a coax jack at the top for an external antenna.
It was clearly designed to function like a 'desk' phone in that the
handset attaches to the base just like you would find in a slimline
POTS phone. Output appears to be (but I can not confirm at this time)
3 watts. It is connected to the alarm control board via the accessory
port (like an ethernet cable port) and power jack. In my case it is
being serviced by Verizion AMPS and even has its own phone number
I
assume it would ring if I rigged it up correctly.
The alarm control board has a number of jacks: POTS in, POTS out,
transceiver, power, battery, and alarm trigger. The phone line from
the house plugs into the board and another cable takes it to the alarm
panel. A standard 12v power supply is used as is a standard 4 or 7 amp
hour gel-cell 12v battery. The unit will not dial out without the
battery. There is an LED that indicates if the unit is 'on line'
meaning that it is providing a dial tone to the alarm panel, if it has
power, and a diag. light that indicates the signal strength and any
trouble conditions. While the hardware is new the firmware on the
control panel is dated 1996.
In normal running mode the phone is not energized and the control
panel is in a wait state. When the panel triggers the board (in my
case when the panel in is LINE CUT condition and there is an alarm to
report) the board energizes the phone and simulates a dial tone to the
alarm panel. The panel sees the dial tone as just another phone line
and dials away. The control board takes care of converting the DTMF
codes to something the cell phone understands and connects the call.
Since the alarm panel knows it is sending over the secondary line it
sends, in addition to the other normal info, a code to tell the CO it
is a cellular report and to not bother calling the land line. One good
thing is that if you get a non-burg alarm like CO or water you get the
full report at the CO even if the land line is down. All in all it
works very well and takes about 2 seconds longer to connect and xmit
the alarm than the POTS line does. There is a medium gain antenna (my
guess is 2-4db) attached directly to the coax port but it would easy
enough to attach a high gain remote antenna if needed.
With a little programming of the alarm panel and/or control panel you
could easily get it to function like the Tellular units and provide a
dial tone to the house phone system. You would just need to be able to
tell the alarm panel to keep that trigger open full time and then
re-route the wires so the hone phone goes into the control board. I
don't plan on playing around with that, however
-D
