The Software Design And Implementation Of Frequency Stability Tester

Frequency stability is one of the main technical specifications for the measurement time reference, which reflects the standard frequency’s own stability and the degree of its sensitivity with various external interference factors. High precision time reference which based on the technology of atomic clock, usually affects the national security and the development level in the related high-tech field. High-precision atomic clock technology requires corresponding measurement techniques of high accuracy frequency stability. Therefore, developed with independent intellectual property rights of a new generation of frequency stability test equipment to meet the needs of the development of China’s atomic clock has important practical significance. To meet the strategy needs of this, this paper base on the existing technology, improve the existing system, combined with the development of software technology and electronic technology, achieve high accuracy automatic measurements of frequency stability.This thesis discusses the system software design and implementation of the frequency stability tester. This article first discusses the principles of the system, structure and functions, then the frequency stability characteristics of the mathematical characterization of systems derived from the signal processing model.The software requirements analysis, using UML (Unified Modeling Language), focus on the software system framework, automated testing procedures and data processing and algorithms. Finally system implementation, results and future work prospects are given.The system software can be generally divided into the underlying control program and application software program. The underlying control program is used to control the counter, collect data, measure the counts of frequency source signal within sampling time, calculate the value of its stability and display. Because the application software program run in computer with a strong computing power and processing speed, so it can be used to obtain the underlying data,then save, process, analysis, output, and automatically control test process. Two software programs via the serial communication interface for data transmission, in this way constitutes a frequency stability automatic test system.This thesis focuses on the underlying control program which coding with the SCM (single chip microcontroller) assembly language.It includes the programs of counter control procedures, DDS control procedures, data collection and calculation procedures, digital LED display program, the communication interface protocols, communication procedures and so on. After testing and improvements, the tester achieved the desired functional requirements, the software is stable, test results are reliable and credible.