효과적인 전류 루프 통신 프로토콜 해석방안에 관한 연구

Among various serial communication schemes, a current loop communication scheme has a merit of robust communication especially for the long distance and in high noise level. This is because the circuit between two ends are separated electrically and fixed current flows through the separated passage. A protocol analyzer is usually used to analyze the interface and the protocol of the serial communications. The protocols of general serial communication such as RS-232C, and RS-422 can be analyzed with the protocol analyzer by attaching probes on the communication line. On the other hands, there are many things to consider to analyze the protocol of current loop communication such as the direction of current, modes (active/passive), completion of the passage, and so on. In this paper, the effective method and cautions are described to analyze the protocol of the current loop communication as well as the brief explanation of the current loop communication.