INTERCOMMUNICATIONS SYSTEM COMPRISING A CENTRAL CONTROLLER UNIT WITH MICROPROCESSORS, COMPUTER SOFTWARE FOR USE IN STORING MESSAGES, CLASS 2 LOW VOLTAGE POWER SUPPLY AND INPUT/OUTPUT CIRCUITS, INTERCONNECTED VIA WIRE CONNECTIONS TO MULTIPLE DESK AND WALL MOUNTED INTERCOM USER STATIONS FOR VOICE AND DATA COMMUNICATIONS, WITH CIRCUITS FOR CONNECTIONS TO EXTERNAL SWITCHES AND CLASS 2 LOW VOLTAGE INDICATOR LAMPS
Electrical and Scientific Apparatus