Help understanding CID protocol

[ymg200@xxxxxxxxxx]

My goal is to equip the new house with alarm system which is monitored
by the central station. I am new to security systems, but once I
started learning about them, my DIY personality started leaning
towards building a system myself.
By doing some research in this discussion group I learned that alarm
systems communicate with the monitoring station by sending CID
signals. If CID is a DTMF sequence, can I generate it using any DTMF
encoder? If I know the CID format that is expected by the monitoring
station, does this mean that I can have a computer to control a DTMF
encoder in order to send code sequences to the monitoring station? Is
there any response from the monitoring station that I need to listen
to, or I can be in "transmit only" mode? Is there any spec to CID tone
length, pause between tones, or any other restrictions?
Thank you.