This is a draft site

The Signal Generating Device (SGD8MD) provides the digital interface between a fire alarm system and the alarm transmitters provided by ADT, AFAM (Automatic Fire Alarm Monitoring) and Alarm NZ.

The SGD8MD can be powered by the local fire panel or DBA power supply or by the alarm transmitter. When the SGD is powered from the local fire panel or DBA supply, only 2 data wires need to be connected to the alarm transmitter. The SGD8MD differs from other SGD units because it has an isolated on-board DC-to-DC converter which enables it to operate with DC supplies where the +ve or -ve terminals are connected to earth.