Method for operating terminals of a digital subscriber connection

摘要

A subscriber interface at the subscriber end of a digital subscriber connection is powered from the exchange via the subscriber connection line, where the power supply is sufficient to supply only a small number of terminals which can be connected via a data line to the subscriber interface. If a plurality of terminals are intended to be connected to the data line, the subscriber interface is to be equipped with an additional power supply device for this purpose. If this power supply device fails, the feed voltage on the data line is reduced for a specific period by the subscriber interface to a first voltage value which differs from the normal feed voltage, whereupon any terminals connected to the data line are disconnected from it. The feed voltage is subsequently increased once more to the normal value. As soon as a terminal accesses the data line, the feed voltage is reduced by the subscriber interface to a second voltage value which differs from the normal feed voltage. This is the criterion which prevents the connection of further terminals to the data line. The individual voltage values are selected in such a way that the second voltage value lies between the first voltage value and the normal feed voltage.