The present system may be most easily understood by referring to the familiar commercial telephone system. As is well known, the telephone system is composed of a number of central offices, each of which is typically located in a city or other population center. Each central office services a number of remote terminals, each of which is located in another smaller population center which may be several miles from the central office. Each remote terminal services a number of subscriber lines and thus is sometimes referred to as a remote concentrator in as much as all of the subscriber lines are brought together for connection to lines running to the central station. For example, there may be 96 lines running from each remote terminal to the central station and there may be 125 subscriber lines (cable pairs) concentrated at the remote terminal. It should be understood that the remote terminal is installed with more lines and cable pairs than are initially needed to allow for growth upon installation. Also spare lines and cable pairs are needed to replace damaged or defective line or cable pairs. To provide service to a subscriber, a spare line from the remote terminal is connected to a spare cable pair going near the subscriber's residence or business.
Each connection of the cable pair to a line, whether for installation, repair, or disconnection, is typically made by hand by telephone personnel dispatched to the remote terminal. This is a very labor intensive operation which entails not only the labor on site but also the time and cost of transporting personnel to the remote terminals.
From the foregoing, it may be seen that considerable effort is required to simply make the proper connection, even when well known terminal equipment is being used. An analogous problem is presented in various applications wherein a number of terminal devices, such as sensors are distributed to provide data or information to a central unit. As in the telephone system, each unit must be individually connected at considerable expense.