PURPOSE: To perform the switching of a transmission line system in use and a spare one without generating hit by providing two systems of delay compensation circuits at the front and rear stages of an elastic store, respectively, performing the bit delay operation of signal sequence based on a delay control signal, and compensating time difference.
CONSTITUTION: When the switching from a system in use to the spare system is requested, a phase difference detection circuit 50 detects a signal that becomes the reference of a transmission line frame signal, etc., and calculates bit quantity in accordance with delay difference between the transmission lines of the system in use and the spare system. Furthermore, the delay control signal CNT2 is supplied to the delay compensation circuit 23 of the spare system so as to eliminate phase difference between the signal sequence of the system in use and the spare system, and the bit delay operation of a transmission line signal is performed. Thence, the circuit 50 supplies switching control signals CNT3, CNT4 to a clock switching circuit 30 and a signal sequence switching circuit 40, and switches a clock signal from the clock signal CL1 of the system in use to the clock signal CL2 of the spare system. After that, bit switching from the transmission signal sequence of the system in use to that of the spare system is performed at every bit unit. Thereby, the switching of the system from the one in use to the spare one without generating the hit can be completed.
| JP2611805 | [Title of Invention] Transmission line switching method |
| JP2002182943 | PACKAGE FAULT DETECTION CONTROL SYSTEM |
| JPH05110543 | DATA COMMUNICATION SYSTEM |
TAKARAGAWA KOJI
NAKAGAWA SEIJI
| JPS5797749A | 1982-06-17 |