A small business.

The customer operated a small workshop with occasional use of noisy machinery and/or tools.

The two exchange lines were wired to the two modular sockets. One horn speaker and two strobe lights were provided. The strobe light gave a visual indication of an incoming call during periods of high ambient noise.

A PIR normally-closed motion-detector sensor placed across the entrance doorway was wired to screw terminals 3 & 10 allowing the Universal Alarm to be used as an "entry" alarm. J1 was bridged, giving a momentary alarm whenever someone entered the premises.