The 300PBX–SC telephone system interface allows access from a PABX (Private Automatic Branch Exchange) to a SelecTone system or centrally amplified paging system. A single standard RJII modular jack is the only input required.

The 300PBX–SC is assigned a dedicated line in place of a telephone. By dialing the extension to which the 300PBX–SC is connected, direct paging access is made to the SelecTone command unit. When the connection is made, a tone is sounded both in the phone and the SelecTone speaker amplifiers. The 300PBX–SC will automatically disconnect when the dial tone is heard or after the pre–determined time limit has expired.

The Model 300PBX–SC includes both an audio output and a double–throw relay circuit to activate the music mute or other function during page. The audio output is a 600 ohm balanced line for direct connection to an audio amplifier. A high impedance output with level adjust is also provided. The controls can adjust the Alert Tone Level, Paging Access Time, Dial Tone Sensitivity and Dial Tone Trip Time.

The cadmium–plated housing can be mounted to most surfaces by means of a #6 screw through the holes in the mounting flanges.

Federal Signal's 300PBX–SC Station Level Paging Adapter saves money by linking an existing phone system to a public address system or SelecTone system.