| 摘要 |
966,341. Telegraphy. STANDARD TELEPHONES & CABLES Ltd. June 16, 1961 [June 20, 1960], No. 21835/61. Heading H4D. The invention provides a system in which there is a receiver which can accept and store data received in any of a number of different codes, and a retransmitter which can retransmit the stored data in any of a number of different codes. Start and stop bits are deleted at the receiver, and, if required, are reinserted at the retransmitter. Fig. 2 illustrates an embodiment which can accept and retransmit in 5-unit synchronous or 7-unit non-synchronous code. Signals received on rj are centre-sampled at 23 by pulses from timing unit 47. Signals S, T are initiated in accordance with the signals being receivedsignal S for 5-unit code and signal T for 7-unit start-stop code. In the case of 7-unit code the sampled signals pass to stage 1R6 of register 1R. As a character is received the register fills, and when the start bit leaves 1R1, 1R1-1R5 will contain the data bits and 1R6 the stop bit. During the stop bit the five data bits are transferred via gates 1G controlled by pulse g to register 2R and from thence passed to the exchange 6. In the case of 5-unit code, the sampled signals pass to stage 1R5 of register 1R, and pulses g occur at every fifth bit rather than at every seventh, the timing unit 47 being controlled by S and T. In a modification, the sampled signals are passed directly to the relevant stage of register 1R by means of a distributer controlled by timing unit 47. The retransmitter receives serial 5-unit signals from the exchange 6 and stores them in register 1R. The signals pass via gates 1G, in response to signals g, to register 2R and from thence to distributer 63 which passes the signals to line tk either as 5-unit signals or as start-stop signals, as selected by signals S or T. The recurrence period of g depends on S and T. The start and stop bits added may be varied from character to character, according to a predetermined sequence. The distributer unit 63 is described in detail with reference to Fig. 8 (not shown), and comprises gating arrangements fed by timing signals from unit 58 to evolve the synchronous or non-synchronous signals. Signals S and T may be manually selected, by push-button, or automatically selected. Fig. 9 (not shown) illustrates an arrangement of gates and triggers whereby a signal S or T is generated automatically. For example, when signal T is being generated each received combination of 5 bits is inspected, and if a particular combination is found the arrangement immediately changes to provide a signal S. Specification 790,914 is referred to. |
