Patent GB-1250080-A (GB)
IPC: H04M5/18
Filed: 1969-09-30
Abstract: 1,250,080. Automatic exchange systems; magnetic storage arrangements. SIEMENS A.G. 30 Sept., 1969 [1 Oct., 1968], No. 47901/69. Headings H3B and H4K. In a line identifier or class of service determining arrangement each line terminal of a line distribution frame is coupled to a rectangularloop magnetic core common to a small group e.g. 10 of subscribers, this core is coupled to another core common to a group of first cores e.g. 10 cores, and so on, the number of cores in any branch of the so-formed tree of cores being equal to the product of the number of cores in each of the remaining branches of higher level and the number of branches being one less than the number of digit places in the multi-place number to be identified. The multi-place number is read-out by successively interrogating the branches starting with the largest, each interrogation stepping a marking, initially, applied from the line terminal to one core in the lowest (i.e. the largest) branch, on to the next branch in the manner of a stepping register. It is stated that for a 10,000 line system a conventional identifier requires 0À7 cores per terminal whereas the present invention utilizes 0À111 or less cores per terminal. Additionally the problems inherent in the use of coincident halfamplitude pulses for interrogation and the expansion of the identifier during exchange growth are overcome. First embodiment (Fig. 2)-The lowest branch SZ of the tree comprises 1000 cores arranged in groups of ten, each core being threaded by inlet wires pertaining to 10 lines and each wire being terminated in the multiple LV on a wire common to the digital value of the lowest placed digit i.e. the units in the number associated with the inlet wire. Each group of SZ cores is coupled to one of the 100 cores SHy these also being arranged in groups of 10. The outlet wires from the SZ groups after threading an SH core are terminated in another common multiple LV on a wire common to the digital value of the second lowest placed digit i.e. the tens in the number associated with the inlet wire. Each group of SH cores is coupled to one of the ten ST cores. The outlet wires from the SH groups after threading an ST core are terminated in yet another common multiple LV on a wire common to the digital value of the third lowest placed digit i.e. the hundreds in the number associated with the inlet wire. Finally each ST core has an outlet wire terminated on a terminal pertaining to the fourth lowest placed digit i.e. the thousands in the number associated with the inlet wire. In operation, a marking on inlet AD999 say changes the state of the associated core 9 in the SZ core group 09 and marks the outlet units wire 9E. A strobe pulse r/ab1 resets the marked core whereby core 9 in the core group SHO is set and a marking is applied to outlet tens wire 9Z. Another successive or possibly co-extensive strobe pulse r/ab2 resets the marked core whereby core O in the core group ST is set and a marking is applied to outlet hundreds wire 9H. Finally a strobe pulse r/ab3 resets the marked core whereby outlet thousands wire OT is marked. Second embodiment Fig. 3. Here, each group of cores SZ contains only five cores which are each threaded by twenty inlet wires while each of the ten cores in an SH group are threaded by only five outlet wires from the preceding SZ groups. A marking on inlet AO99 say, sets core 5 in group SZO and marks units wire 9 in the multiple LV2 pertaining to the odd tens digits thereby setting core KE9 and odd-indicating core KU (contact id is closed during an identification). A strobe pulse r/ab1 resets the core SZ9-5 thereby setting cores SH-9 and KZ8/9, the latter via wire 8/9 in the multiple LV. Finally strobe pulse r/ab2 resets core SH-9 thus causing hundreds wire 9H to be marked and also resets cores KZ8/9, KU and KE9, thus causing the odd-tens wire 9Z and the units wire 9E to be marked. Application to exchange Fig. 1. A seized junction Ue causes finder SW to connect up an identifying pulse generator to the c-wire in the connection extending from the junctor to the subscriber's appearance on line distribution frame Vh. Consequently one of the terminals A in the identifier AF (c.f. Fig. 2 or 3) is marked. Preferably during the early part of this marking an erase pulse r is applied to the identifier by the first stage of a counter in the central control. The counter's steps 3-5 produce the aforementioned strobe pulses rab 1-ab3. At steps 6 and 7 pulses w and k are effective to shift the decoded number into a store AE and to effect an ambiguity check in device KE. If there is any fault in the number e.g. two wires in a same digital group marked, then bi-stable BK1 is set via lead f so as to start the identification process again, a further fault causing an alarm to be given on lead st (delay line VZ1 storing the fault indication from the first attempt). If there is no fault lead e is marked so as to start a second counter which repeats the identification process (steps 9-12). Transfer is effected by pulse w at step 13 and an ambiguity check is effected by comparing the two numbers in store AE at step 14. If there is any fault the whole process is repeated again. If the fault is resolved the number in store AE is released for further processing, otherwise the identification is abandoned and an alarm is initiated (bi-stable BK2 and second st lead). Details of transistor and diode circuits for decoupling the cores and for amplifying pulses therethrough are depicted in Figs. 4-6 (not shown).