KOPPLINGSANORDNING FOER PROEVNING AV FUNKTIONSDUGLIGHETEN HOS EN DATAOEVERFOERINGSANORDNING.

摘要

A circuit arrangement is provided for completely testing the operability of a data transmission facility which has a four-wire connected to a two-wire line via a hybrid and in which an echo compensation circuit is connected between the data signal output line and the data signal receiving line of the circuit arrangement. The data signals appearing on the data signal output line are supplied to the hybrid without delay as well as delayed by a fixed time interval which is selected to exceed the longest time leading to a correlation between delayed and undelayed data signals. The echo compensation circuit is driven only with the delayed data signals.