Design and implementation of a general-purpose precise sync source

A design scheme of a general-purpose precise sync source is presented to meet the demand of the synchronous control and sampling for high-precision sync source. According to the adaptive control principle, output parameters of oven controlled crystal oscillator and the pulses per second (PPS) signals of GPS are identified and processed by using the CPLD and single-chip microcomputer. Therefore, a high-precision sync clock signal with settable frequency is formed. Compared with the solution of using the PPS signal or crystal oscillator as the sync clock, this scheme eliminates the negative effects on the sync precision imposed by the interference and the uncertain drift of the crystal oscillator. Experimental results show that the scheme is feasible, and especially suitable to the remote distributed measurement and control system.