SYNCHRONISATION ARRANGEMENT FOR EQUIPMENT CONNECTED TO THE PUBLIC TELEPHONE NETWORK

摘要

In a transmission system in which information has to be transmitted from a first device (2) to a second device (6) and vice versa, use is made of a first part (t0-t3) of a timeslot to transmit data from the first device (2) to the second device (6) and from a second part (t3-t4) of the timeslot to transmit data from the second device (6) to the first device (2). In order to obtain correct operation of the system, the second device (6) has to be synchronized to the first device (2). This is done by using a phase locked loop (78) which locks on the signal present on the interconnection lines between the first device (2) and the second device (6). In order to ensure reliable synchronization the second part of the timeslot (t3-t4) ends before the beginning (t5) of the first part of the next timeslot and a rising edge is present at the beginning (t5) of the first part of each new timeslot.