| 摘要 |
The invention relates to an arrangement comprised in a digital group selector of the time-space-time type in a telecommunication system in which the connected subscribers communicate with each other in specially allocated time slots. The group selector comprises time selector modules TSM and space selector modules SPM which are arranged at geographically different distances from each other and from a clock signal unit CLM that provides clock signals to the modules for controlling these. In order to even out the time differences between the different units, at all inputs and outputs connected to time selector modules TSM each space selector module SPM is provided with separate time delay circuits K for compensating for time differences caused by different length of the cables that transmit signals between the clock signal unit CLM and the selector modules and between the different time and space selector modules. The compensating circuits KH, KA, KV contain a number of series-connected registers R, and, by means of looping in these circuits, a delay is obtained corresponding to a particular number of time slots so that the signals from a time stage TSM0 appears at the intersection of the space selector matrix in phase with the clock pulse that the space selector receives from the clock pulse source, and so that the signals that are supplied from an intersection in the space selector to a time stage TSM1 appear in phase with the clock pulse that the time stage receives direct from the clock pulse source. <IMAGE> |
