Intended for use by equipment in security industry alarm monitoring centers, with possible uses in the areas of energy control and facilities monitoring and management. Provides a common interface format for across-the-board compatibility of equipment, regardless of manufacturer, and provides for all the known communication needs between the computer and receiver. Defines basic 'codes' to identify commonly used dialer protocols used in alarm signal transmitters, as well as conditions in the central station equipment that require a technician or other manual attention.