Abstract

A system, consisting of a plurality of Remote Monitoring Units and a Central Computer, for automatically monitoring the selection of a Program Source made by a Subscriber. Each Remote Monitoring Unit has a microprocessor, associated Program and Data Memory, and Control and Interface circuitry. Each of the remote monitoring units maintains a software implemented real-time-clock. When a selection has been made by a Subscriber, the time of day and channel identification (ID) is recorded in the onboard memory.Communication with the central office computer is initiated by the remote monitoring unit at preprogrammed intervals over the conventional voice telephone network using the individual Subscriber's telephone line. Communication with the central office computer is via frequency shift keyed audio tones. The data sent is the information required to generate billing based on Subscriber viewing, and consists of a unique identity code for each monitoring unit, the channels selected by the Subscriber, and the time of each selection. The remote monitoring unit is capable of receiving messages from the central computer and retransmitting the stored data in the event of an unsuccessful contact, as well as disabling the program selector and access device on command.The remote monitoring unit accesses the Subscriber's telephone line via an integral telephone interface device, and avoids conflict with normal use of the telephone line.