The Technology of FSO and its Application Analysis;

Wiretapping,which is technical,secret and enforceable,will inevitably impairs the freedom of speech,the freedom of communication and privacy of individual citizens if it is used beyond necessary.

Application of MAX3100 in Infrared Communication;

An ultrasonic distance measurement instrument with infrared communication interface was introduced,which can measure accurately and display distance,memory data,and communicate with PC.

The paper introduces an application of infrared communication system in vehicle teStingline.

Aimed at the problem presented in the communication between upper-computer and S7-200 series PLC,this paper introduces the freeport communication and data transmission between PLC and PC.

s:In this article, taken the SIEMENS′ S7-200 PLC for example, the communication between PLC operating in freeport communication and host computer with Visual Basic are achieved.

For the free-port communication between S7-200 PLC and computer,computer send many kinds of data to PLC,this article designs a method of using multi-index to receive and save the data in PLC,the data irrespective with computer′s operation is decreased greatly,computer′s command data can .