ultrasonic

IEC 60870-5-101 通信规约英文版规范(IEC 60870-5-101-2003 Telecontrol equipment and systems Part 5-101 Transmission protocols)

this is a paper for pcf beam splitter!

多功能电能表通信协议_645-2007.pdf(Multi-function watt-hour meter communication protocol _645-2007.pdf)

gardner位同步算法，实现数字通信系统中位同步(gardner bit synchronization algorithm to achieve bit synchronization in a digital communication system)

基于ARM的嵌入式程序设计.rar,对arm的学习会有很大的帮助。(ARM-based embedded programming. Rar, on the arm of the study will be of great help.)

HART协议解析，非常完整，定能加快研发进度。(HART agreements, some of the information, in the hope that everyone has to help)

说明：  从网上找的SAE J1939 介绍的总结，主要是应用层介绍，包括PGN和SPN的计算及介绍。(Summary and Introduction of J1939.)

如果你第一次使用D12，请先阅读该文档，将会对你的编程有很大帮助。(if you use the PDIUSBD12 first time ,please read this file first.)

杨建国老师的通讯原理课件，第三章模拟信号的调制与解调，主要讲述信号产生与调制，射频特性，解调，MSK、GMSK、PSK、QPSK、BPSK、QAM等原理(Yang Jianguo teacher communication principles of courseware, the third chapter of the analog signal modulation and demodulation, and focuses on the signal generation and modulation, the RF characteristics, demodulation, MSK, GMSK, PSK, QPSK, as BPSK, QAM and other principles of)

西門子CNC系統編程代碼表,對初學者幫助很大(Siemens CNC system control code )