Remote-testing arrangement for PCM transmission system
First Claim
1. In a pulse-code-telecommunication system including a pair of head stations interconnected by a set of parallel two-way transmission channels, a set of line terminals at each head station respectively connected to said transmission channels, and a plurality of cascaded relay stations between said head stations, each relay station encompassing a set of line repeaters respectively inserted in said channels, the line terminals of one head station being adapted to transmit over the associated channel a test code for checking a selected line repeater inserted therein, each line repeater being provided with loop-closing means for retransmitting said test code to the originating line terminal,the combination therewith of:
- a service link extending from said one head station to all said relay stations;
a monitoring unit at each relay station connected to said service link;
signal-generating means at said one head station connected to said service link for transmitting thereover an address code identifying the monitoring unit of a relay station containing the selected line repeater;
discriminating means at each monitoring unit responsive to the corresponding address code for delivering a priming signal to all the line repeaters of the relay station so addressed;
receiving means at each line repeater responsive to said test code for emitting a recognition signal; and
coincidence means at each line repeater connected to said receiving means and to said monitoring unit for operating said loop-closing means under the joint control of said priming and recognition signals.
1 Assignment
0 Petitions
Accused Products
Abstract
Two sets of line terminals in a pair of PCM head stations are interconnected by a set of transmission channels via a number of cascaded relay stations each including a line repeater for each channel. A service link extends from an address generator in one head station to a monitoring unit in each relay station, the monitoring unit including a regenerating circuit for throughgoing address codes and further including a discriminating network which, upon detecting an address code identifying that relay station, sends a sinusoidal priming signal to all the associated repeaters. A predetermined PCM test code, e.g. one containing a certain number of consecutive zeroes, is simultaneously transmitted from the same head station over the channel containing a selected repeater to be checked which, upon coincidence of the test code with the priming signal from the associated monitoring unit, closes a loop for feeding back the test code to the originating line terminal.
21 Citations
10 Claims
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1. In a pulse-code-telecommunication system including a pair of head stations interconnected by a set of parallel two-way transmission channels, a set of line terminals at each head station respectively connected to said transmission channels, and a plurality of cascaded relay stations between said head stations, each relay station encompassing a set of line repeaters respectively inserted in said channels, the line terminals of one head station being adapted to transmit over the associated channel a test code for checking a selected line repeater inserted therein, each line repeater being provided with loop-closing means for retransmitting said test code to the originating line terminal,
the combination therewith of: -
a service link extending from said one head station to all said relay stations; a monitoring unit at each relay station connected to said service link; signal-generating means at said one head station connected to said service link for transmitting thereover an address code identifying the monitoring unit of a relay station containing the selected line repeater; discriminating means at each monitoring unit responsive to the corresponding address code for delivering a priming signal to all the line repeaters of the relay station so addressed; receiving means at each line repeater responsive to said test code for emitting a recognition signal; and coincidence means at each line repeater connected to said receiving means and to said monitoring unit for operating said loop-closing means under the joint control of said priming and recognition signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification