Step-by-step remote locating system for repeaters in a PCM link

In a remote station of a system for step-by-step remote locating pairs of first and second amplifying means at the remote station, the first and second amplifying means being respectively included in first and second transmission channels of a bidirectional digital transmission medium between first and second end means, the first end means generating on said first channel remote locate sequences composed of first interruptions in a digital signal conveyed by said first channel and generating a locate end interruption in said digital signal on said first channel,

• each interruption being longer than the duration of the maximum series of consecutive zero digits that said digital signal can contain and each of said first interruptions being shorter than said locate end interruption,
• each of said remote locate sequences being intended to command closing of a loop-back path between said first and second amplifying means of the respective pair and including (a) a predetermined integral number k (k.gtoreq.2) of first nonconsecutive interruptions during a predetermined period of time, and (b) with the exception of the first sequence generated and intended to command the nearest amplifying means pair of said first end means, an interruption which precedes said first interruptions of said sequence and which is intended for opening said loop-back path of the preceding amplifying means pair,
• the combination of:
• detecting means for detecting said locate end interruption,
• detecting and counting means for detecting and counting said first interruptions for closing the loop-back path when the count of said detecting and counting means is equal to k, and for opening the loop-back path when the count of said detecting and counting means is different from k,
• and means for returning said detecting and counting means to zero in response to a count less than k during said predetermined period of time or in response to a locate end interruption being detected by said detecting means.

A remote station of a system for step-by-step remote locating pairs of first and second amplifying means respectively included in first and second transmission channels of a bidirectional digital transmission medium between first and second end means, the first end means generating on said first channel remote locate sequences composed of first interruptions in a digital signal conveyed by said first channel and generating a locate end interruption in said digital signal on said first channel,

• each interruption being longer than the duration of the maximum series of consecutive zero digits that said digital signal can contain and each of said first interruptions being shorter than said locate end interruption,
• the station comprising:
• the first and second amplifying means,
• a loop-back path selectively closed between the first channel and the second channel for connecting at least one of the first and second amplifying means to be responsive to the signal received at the station,
• each of said remote locate sequences being intended to command closing of the loop-back path between said first and second amplifying means of a respective pair and including (a) a predetermined integral number k (k.gtoreq.2) of first nonconsecutive interruptions during a predetermined period of time and, (b) with the exception of the first sequence generated and intended to command the nearest amplifying means pair of said first end means, an interruption which precedes said first interruptions of said sequence and which is intended for opening said loop-back path of the preceding amplifying means pair,
• detecting means for detecting said locate end interruption,
• detecting and counting means for detecting and counting said first interruptions for closing the loop-back path when the count of said detecting and counting means is equal to k, and for opening the loop-back path when the count of said detecting and counting means is different from k,
• and means for returning said detecting and counting means to zero in response to a count less than k during said predetermined period of time or in response to a locate end interruption being detected by said detecting means.