Method for detecting faults in regenerators in a pcm-system

Claim 2

Method for detecting faults in the links between firSt and second terminals of a PCM transmission system wherein the pulse trains are transmitted via at least one stage of regeneration in each direction comprising the steps of: for fault location in a first link having a transmission direction from the first terminal to the second terminal, transmitting from the first terminal on the first link a pulse train including first pulse trios, the three pulses of each first pulse trio having alternating polarities with the first pulse of each such trio shifting polarity in synchronism with a pass frequency selected and allotted to the one stage of regeneration, filtering the first pulse trios regenerated by said one stage to select a sinusoidal signal having the selected pass frequency, and transmitting the selected sinusoidal signal, if present, to indicate that the transmission from the first terminal through the one stage of regeneration was fault free; and for fault location in a second link having a transmission direction from the second terminal to the first terminal, transmitting from the first terminal on the first link, a pulse train including pulse duos, the two pulses of each pulse duo having opposite polarities, and the first pulse of each pulse duo shifting polarity in synchronism with said selected pass frequency, at the second terminal converting the pulse duos to second pulse trios having the same properties as the pulse trios transmitted from the first terminal during the fault location in said first link, transmitting from the second terminal the second pulse trios on the second link, filtering the second pulse trios regenerated by the one stage in the second link to select a sinusoidal signal having said selected pass frequency, and transmitting the selected sinusoidal signal, if present, to indicate that the transmission from the second terminal through the one stage of regeneration in the second link was fault free.

Claim 3

The method of claim 1 wherein are a plurality of stages of regeneration in each link and wherein each stage in each of the links is assigned a different pass frequency, further comprising, when generating the first pulse trios and the pulse duos, generating such pulses to be sequentially in synchronism with each of the different pass frequencies and when filtering at each regeneration to select the pass frequency assigned to the stage.

Claim 4

In a PCM system having a first and second terminal connected by at least a first link for transmitting pulses in a first direction from the first terminal to the second terminal and at least a second link for transmitting pulses in a second direction from the second terminal to the first terminal, and having a plurality of regenerator stages, each of the regenerator stages having an amplifier for each of the links and a filter for receiving signals from all of the amplifiers in the stage, the filter of each of the stages having a unique pass frequency associated with the stage, means connected to the outputs of all the filters for receiving the pass frequency signals from the filters to indicate the operativeness state of the regenerator stages, and at the first terminal for connection to said first link, a first generator means for sequentially generating a plurality of different packets of pulses wherein each of said packets is associated with a different one of said regenerator stages and wherein each packet comprises a plurality of pulse trios with the three pulses alternating in polarity and the first pulses of the trios shifting polarity in synchronism with the pass frequency of its associated stage, so that the location of faults in said first link can be indicated, apparatus for indicating the location of faults in said second link comprising at the first terminal means a second generator means for sequentially generating a plurality different second packets of pulses wherein each of said second packets is associated with a different one of said regenerator stages and wherein each of said second packets comprises a plurality of pulse duos with the two Pulses of each duo having opposite polarities and interchanging polarities in synchronism with the pass frequency of its associated stage, means for selectively connecting said second generator means to the first link to the exclusion of said first generator means, and converter means in the second terminal having an input connected to said first link and an output connected to said second link and including means for converting pulse duos received from said first link to pulse trios for transmission on said second link.

Claim 5

In a PCM system having a first and second terminal connected by at least a first link for transmitting pulses in a first direction from the first terminal to the second terminal and at least a second link for transmitting pulses in a second direction from the second terminal to the first terminal, and having a plurality of regenerator stages, each of the regenerator stages having an amplifier for each of the links and a filter for receiving signals from all of the amplifiers in the stage, the filter of each of the stages having a unique pass frequency associated with the stage, means connected to the outputs of all the filters for receiving the pass frequency signals from the filters to indicate the operativeness state of the regenerator stages, and at the first terminal for connection to said first link, a first generator means for sequentially generating a plurality of different packets of pulses wherein each of said packets is associated with a different one of said regenerator stages and wherein each packet comprises a plurality of pulse trios with the three pulses alternating in polarity and the first pulses of the trios shifting polarity in synchronism with the pass frequency of its associated stage, so that the location of faults in said first link can be indicated, apparatus for indicating the location of faults in said second link comprising at the first terminal means a second generator means for sequentially generating a plurality different second packets of pulses wherein each of said second packets is associated with a different one of said regenerator stages and wherein each of said second packets comprises a plurality of pulse duos with the two Pulses of each duo having opposite polarities and interchanging polarities in synchronism with the pass frequency of its associated stage, means for selectively connecting said second generator means to the first link to the exclusion of said first generator means, and converter means in the second terminal having an input connected to said first link and an output connected to said second link and including means for converting pulse duos received from said first link to pulse trios for transmission on said second link.

Claim 6

The apparatus of claim 3 wherein said second pulse generator means receives pulse trios from said first pulse generator means and includes means for converting the pulse trios to pulse duos.

Claim 7

The apparatus of claim 3 wherein said first pulse generator means receives pulse duos from said second pulse generator means and includes means for converting the pulse duos to pulse trios.