Abstract: A remote surveillance and fault location unit for installation in each pulse generator repeater in a digital transmission link uses a service signal added to the digital data signal conveyed by the link. Each unit comprises a receiver circuit (100), a time base (200) and a transmitter circuit (300) suitable for implementation as an integrated circuit. The units add data representative of the performance of the repeater at which they are located to the service signal which is then monitored at one end of the link. The remote surveillance and fault location unit comprises a receiver circuit connected to an input to the pulse generator repeater for receiving a service signal if one is present at the input, a carrier frequency and clock bit frequency recovery circuits, a transmission circuit having its output connected to a second input of the pulse regenerator repeater for transmitting a service signal corresponding to the received frame to which data has been added.

Abstract: The invention concerns regenerative repeaters for pulses. The method consists of detecting errors, coding them and recording them in a channel of a tele-locating frame. Each regenerative repeater of a connection has a channel which is attributed to it, for example channel i, for the repeater whose order is i. The device implementing the method comprises means for directing the tele-locating signals at the input of the repeater, memorizing them and applying them to a low-frequency modulator which reinjects them into a directing means at the output of the repeater; it comprises also means for detecting the channel whose order is i and recording therein the coded proportion of error of the repeater.