Will it work on my system (or telephone)?

The Universal Alarm (as is any other alarm or loud bell) relies on an analogue ring signal of around 40-70V at a "normal" frequency and periodicity. They will therefore not work on a digital system (or a digital extension) because the "ring signal" is just a binary string.

If you can get a T200 or a buttinski to ring on the circuit you want to connect the alarm to, the Universal Alarm will work OK. If the test telephone won't ring, neither will the alarm.

In mid 2006 the unit's programming was altered to make the alarm more compliant with the simulated exchange-ring produced by PABX systems. The Universal Alarm will now work reliably when connected across an analogue ports of most PABX systems. The newer programme produces a broken output-signal cadence (i.e. if you hold down one of the test buttons and get a continuous output tone, then your unit has the original programming. If the output tone is broken into bursts then you unit has the newer programming. If you have an "original programmed" unit and are not having success with an analogue port on a particular PABX, try one of the "newer programmed" units.