| 摘要 |
1,270,827. Automatic exchange systems. WESTERN ELECTRIC CO. Inc. 5 June, 1969 [11 June, 1968], No. 28441/69. Heading H4K. In a telecommunication system, dial pulse information from a progressive exchange, e.g. step by step, can be sent to an exchange which stores the information prior to using it, e.g. No. 1 ESS, by providing on each trunk line a network which delays all the incoming pulses by a predetermined time. An off-hook condition at an originating office OR is sensed by trunk scanner S1 and causes central control CC to cause the line to be connected to an idle dial pulse receiver DPR through trunk link network TLN and junction WJ. If the OR is an electronic exchange, CC arranges for the incoming trunk circuit ITCI to be put into a by-pass condition and a ready signal sent to the originating office. The ferrod scanner is maintained in an energized state while the DPR is detecting dial pulses and storing them in the call store CS. When the number is complete, the central control CC acts on the information to set up the necessary conditions. In the case where the OR is of the step-bystep type the dial pulses are delayed at the incoming trunk circuit ITCI for sufficient time to ensure that the output of the trunk circuit is connected to the dial pulse receiver. As shown in Fig. 3, a dial pulse relay P applies a signal to the C or S input of the first stage of a shift register STG 1-n which is advanced by applying pulses from oscillator OSC 1 to the toggle input 1 of the register. The delay time is determined by the number of register stages and the shifting frequency used and since the time required to make the necessary connections depends on the traffic load of the exchange, a second oscillator OSC2 having a lower frequency output may replace oscillator OSC1. The output from the multistage register is switched on by transistor TR and the pulses pass to the DPR from the output of ITCI to set up a call connection in the usual way. |
