Data extraction system for PCM TDM signals - has exchange and data clock synchronised systems with random phase relationships switching from clock to inverted clock synchronism

摘要

A reliable method is used for extracting information from PCM time multiplex exchange systems in which there issynchronism of exchange clock and data bit clock signal, but with random phase relationship. It s especially applicable with an exchange system comprising a number of largely autonomous modules. Extraction is effected alternatively with the exchange clock rate or its inverse value with a switch over from one arrangement ot the other if the active flank of the timingsystem operative at any instant coincides with one flank of the PCM information to be extracted.