In order to improve the performance of computer controlling system, perfect the transmission mode of inter-station information and the transmission capability, and meet the future development, the paper researches the safety transmission scheme to guarantee inter-station information transmission through Secure Hash Algorithm - SHA-1 by combining various inter-station communication modes.
This paper simply introduces some communication modes in automatic meter reading system. And with the development of network technology, wireless communication technology based on GSM network comes to be applied to the power system. Because of its untouchable advantage,it has a bright future.
After analyzing the characteristic of information stream and communication of the system and network communication modes in Windows operating system, UDP protocol and Winsock OCX control are adopted to implement the high-speed network communication of this system.
As one of main communication modes, RS232 serial interface has been applied in many types of equipments, such as instruments, controllers and remote terminals, for long time. For these equipments could be used in the future, this status may not match with the popular USB (Universal Serial Bus) bus interface well.
在过去的很长时间内，RS232串行接口方式是诸多仪器仪表、控制终端、远程终端等设备的主流通讯方式之一，与现在流行的上位机(如PC等)的USB(Universal Serial Bus)总线接口方式不相适应。
Some communication modes of PLC were discussed. As an example,the communication between AT89C51 and C200HE(PLC) produced by OMRON was explicated,including physical structure,communication settings and program design.
We adopted Various Communication Modes in this system, used the GSM AT instructions and CMPP by combining Internet and the network of Wireless Transmission to realize the transmitting and receiving of short message service.
The vehicle monitoring and dispatching system of various communication modes based on the GPS/GIS/GSM designed in this paper is made up of the vehicle unit, wireless communication system and controlling center.