Patent GB-1032068-A (GB)
Title: Improvements in or relating to signal monitoring systems
IPC: H04M/
Filed: 1963-09-27
Abstract: 1,032,068. Automatic exchange systems. SIEMENS & HALSKE A.G. Sept. 27, 1963 [Sept. 28, 1962; Jan. 2, 1963], No. 38093/63. Heading H4K. Signalling means (such as groups of lines in an exchange system) are scanned at a speed which is slow enough for a signal pulse (such as a metering pulse) to be detected but too fast for the origin of the pulse to be identified or for the pulse to be stored, and detection of a signal pulse causes the scanning means to stop at the signalling means which produced the detected pulse for sufficient time to allow the origin of the pulse to be identified and the pulse to be stored in accordance with this identification. As shown, Fig. 1, metering leads L11-Lyx are connected to corresponding AND gates K11-Kyx, arranged in a matrix of which each row is pulsed in turn by a scanner AW1 driven by pulses on lead WT. Coincidence of a scanning pulse with a metering pulse produces a signal at the output of one of the amplifiers V1-Vx, this signal being fed to an intermediate store ZSP and also driving a trigger circuit B1 to its operative state in which it blocks gate St, thereby stopping the scanner AW1. A rotating magnetic drum SP, having a separate storage track for each row of the matrix K11-Kyx, sends a marker pulse through an amplifier Vta at the start of each revolution. When trigger B1 is switched on, this marker pulse opens AND gate Gta and switches on a second trigger circuit B2 which opens that one of gates G1-Gy which corresponds to the matrix row at which scanner AW1 has stopped, thus setting a selector SW to the corresponding track on drum SP. The items of information on this track are read out through amplifier LV and read back through amplifier SV into their former positions, in synchronism with the scanning of intermediate store ZSP by a scanner AW2 driven by pulses sent from drum SP through amplifier Vt and AND gate Gt, which has been opened by the switching on of trigger B2. When scanner AW2 encounters a stored metering pulse in ZSP, it causes the addition (in adding stage AD) of one unit to the information in the corresponding position on drum SP. When scanner AW2 finishes scanning store ZSP it switches off triggers B1 and B2 so that scanner AW1 resumes its operation. A ferrite-core memory may be used in place of the magnetic drum SP. In a second embodiment, Fig. 2, pulses on a lead WT drive a scanner AW which tests in turn each of a set of AND gates SS1-SSy connected in the trunks of a group selector stage I.GW. When a scanning pulse coincides with a metering pulse (from a contact zi), the relevant gate SS sends a pulse through the line circuit TS of the connected line to a decoder assembly DK which produces a combination of outputs corresponding to the number of the line. This number is fed to a checking unit MP which, if it finds the number unambiguous, signals over its output r to switch on a trigger circuit B (stopping the scanner AW) and also to open gates S1-S3 so that the line number is sent to a recording unit AE; this unit, on completion of its operation, switches off trigger B and scanning is resumed. If, however, the checking unit MP finds the received line number ambiguous, it signals over its output w to stop the scanner AW by means of trigger B and to cause a pulse generator JG to produce a simulated scanning pulse. If this repeated scanning still produces an ambiguous result, the checking unit MP over its output al causes a warning unit AL to indicate the position of scanner AW and hence of the faulty transmission channel. Trigger B is then switched off and scanning continues.