| 摘要 |
1,186,317. Digital transmission systems. SIEMENS A.G. 12 June, 1968 [13 June, 1967], No. 27818/68. Heading H4P. In a digital data exchange containing a number of storage stages, e.g. ES, ZS, the data is transferred between the stages at a higher speed than that at which it is received. The exchange has several output lines, e.g. 121, 122, going in the same direction, and it is arranged that the stores in any storage stage except the input stage ES are selected successively so that initially successive data items to be forwarded in that direction are passed to separate stores. Each data item on 11 passes to input stores ES from which it is passed at higher speed to one of the stores in stage ZS. The store is selected by unit CE which evaluates the called address stored in ES and controls switch ESK. Unit SLV determines in cyclic sequence which of the output lines are free and, via unit ZA and switch ZVK, connects the first free line to the store in ZS containing the data. The store is then read out at the required speed to the chosen line. If transmission is in progress from a store in ZS then input to that store is blocked by way of units SLV and ZVS. If a further data item now arrives unit ZVS ensures that it is passed to a free store in ZS. Only if all the lines going in the same direction (and consequently the stores in ZS) are in use does unit ZVS make available, for subsequently arriving data items, stores in ZS which already contain first data items, and only when all the stores are filled with second data items can any store be filled with third data items. |
