Papers by Author: Jin Sheng Sun

Abstract: With the rapid growth of the Internet, the interest for connecting devices such as frequency converters into Internet has increased. Web browser is used by remote operator to control and monitor frequency converters via Internet and this application will be widely utilized. This article makes a study of web-based monitoring for frequency converters with USS interface. It is based on TCP/IP stack and the real time operating systemμC/OS-II. Then this paper presents a detailed analysis of the Web server, and the interactive method of the browser and the Web server. In the design of the server, it emphasizes the USS protocol telegram processing method. The architecture of embedded monitoring system, hardware and software implementation are also described in this article.

Abstract: Hardware connection and software implementation of communication are designed between the S7-200 PLC and Ethernet. Hardware composition is introduced and low-power microprocessor S3C2440 is selected as the control chip, DM9000 as Ethernet control chip, serial port RS-232 as testing interface. Monitoring page is designed to show the status of PLC. PPI protocol is known by analysing the communication process of S7-200 with PC. Embedded web server Boa is transplanted and CGI program is developed in Linux embedded operating system. It can realize the function of reading and writing I/O value and simulation value. The experiment shows that the system can realize reliable serial communication. It brings a great convenience to work.

Abstract: In this paper, the stability of systems with interval time-varying delay is investigated. The time delay varies in an interval. By employing a new and tighter integral inequality and constructing an appropriate type of Lyapunov functional, the delay-dependent stability criteria are derived. Because neither any model transformation nor free weighting matrices are employed in the theoretical derivation, the developed stability criteria significantly improve and simplify the existing stability conditions.