• A single LED lighted switch on the front panel indicates when the relays are active and provides a  means of manually actuating the relays

• A standard IEC power cord provides AC voltage to the unit through a master switch and a resettable circuit breaker. An internal MOV (Metal Oxide Varistor) provides surge protection for the unit in additional to any external surge strip or line conditioning device. The 5 volt DC supply inside is additionally fuse protected on the circuit board.
• A standard parallel printer connector (Centronics 36 pin) allows the use of any ordinary printer cable for the control connection.
• A double pole, double throw relay provides 2 separate sets of normally open and normally closed dry contacts capable of switching up to 5 amps at 125 volts. Clamp style connectors on the back panel simplify hookup.
• A solid state relay provides switched AC voltage to a standard AC socket on the back panel up to 10 amps.

    In the buzzer application a remote PC (actually a time and attendance collection point) is connected to the Corkwerks 400. IBM's Client Access PC software has the capacity to accept incoming remote commands from the AS/400 to run specified programs. A scheduled process on the AS/400, using the same system time as the data collection points, passed a run command to the clock PC. The PC application simply prints a character to the parallel printer port for a predetermined length of time or a time parameterized by the AS/400 process calling the PC application.

    The AS/400 system is isolated from the AC load by the network connection to the PC and further by the printer port and the isolation of the Corkwerks 400's internal relays.