| 摘要 |
<p>In a data-transmission route involving parallel (e.g. 8Mb/s) data-transmission systems each using a separate line pair, a common line pair, linking all terminal and repeater stations, is used for supervisory and control purposes (signals up to say 25 KHz) and each of e.g. 100 repeater stations (provided with a digital regenerator per data-line pair) has a single error-detection and a single interrogate/response signal circuit at the station. Additionally each repeater station has selection means for connecting the output side of any of the regenerators of the station to the error detector which is permanently associated with the interrogate/response circuit. After the identical setting of the selecting means at each repeater station (e.g. by dial signals forthcoming over the common pair or by an audio tone forthcoming over the data transmission path) an interrogate pulse (1mS 25 KHz), also transmitted over said pair from a terminal station, is effective in the nearest repeater station to develop a backward response signal and to advance an interrogate signal to the next (2nd) repeater station. All interrogate and response signals, appropriate to the selected transmission pair at each repeater station, makes use of the common line pair, so that the interrogating terminal station receives over that pair a sequence of signals which serves to report the existence and the location of any reportable transmission faults which develop in the selected data line.</p> |
