Audacity Project file for Ademco emulation.

The ademco composite file presented here is not a true emulation because of the long timscales involved. The true Ademco standard uses a long silence followed by a handshake (100ms of 1400Hz followed by 100ms silence followed by 100ms of 2300Hz). This is repeated here but the initial silence is ~0.5 seconds.

The DTMF phase is preceded by ~250ms min silence and the DTMF has a particular format. DTMF digits 9, 8, 7, 6, 5, 4, 3, 2, 1, C, B, A, #, *, 0 (to the CMX86x data sheet - not Ademco). The tone cadence is ~50ms on 50ms off.

The Ademco standard requires a silence of 1.25s before the kisoff tone. Here ~500ms of silence is used (plenty for the decoder to settle). The kisoff is 750ms of 1400Hz.

If a second message is sent then it should start within 650ms. So normal decode sequence is:
Wait for silence, enable 1400 and 2300 decode.
Check order and cadence length of handshake.
Switch to DTMF decode.
Do decode.
Wait for final DTMF digit to end then wait 700ms (arbitrary).
If no next message DTMF encode in 100ms (arbitrary) switch to 1400 decode.
Wait for kisoff tone.
Check kisoff length then hang up.

A silence of 250ms has been added to the end of the signal for convenience.

The tones are recorded at handshake relative levels:
handshake 0.125, 0.2
DTMF and kissoff 0.125