OPERATION MONITORING OF DIGITAL TRANSMISSION LINKS

摘要

For monitoring the operation of digital transmission links, a frequency-shifted telemetry signal, which consists of individual messages which are regenerated separately from the useful signal in each regenerative repeater and are supplemented by the message of this regenerative repeater, is also transmitted via the transmission device provided for the digital useful signal. To increase the number of transmittable alarm indication messages per regenerative repeater, it is proposed to provide in the telemetry units of the regenerative repeaters an additional sampling switch which circulates cyclically and connects one of the connections carrying alarm indication data with a collecting point for the data block to be sent out with each message cycle and during this process skips all connections which do not carry any alarm indication data at the sampling time.