VB写的通过串口与考勤机连接通讯的程序

北斗卫星接口文件 北斗卫星导航系统 空间信号接口控制文件 （测试版） (Beidou satellite interface file Beidou satellite navigation system space signal Interface Control Document (Beta))

用Visual C++的API函数来打开、关闭串口和设置串口通讯速率等功能。(Visual C++ using the API function to open and close the serial port and set up features such as serial communication rate.)

数字通信技术的收集与介绍 希望对大家有用( Communicate)

ptz 云台控制软件, 内带C++ 源码(ptz PTZ control software, which brought C++ source)

Modbus for Field Technicians 介绍modbus的相当好的资料，包括原理和编程和协议介绍(Modbus for Field Technicians introduction modbus fairly good information, including schematics and programming and protocol description)

作为TCP客户端跟TCP服务端进行通讯，支持modbus协议(As a TCP client to communicate with the TCP server to support the modbus protocol)

说明：  一种PC与单片机多机RS232串口通信设计应用(A PC with a single-chip multi-machine RS232 serial communication design application)

Sample code in VB.NET for calculate and check CRC (Modbus specification). Supported both string format (like MSComm) and bytes array(like DCB).

说明：  基于modbus rtu封装的通讯协议，很好用(Communication protocol based on Modbus RTU encapsulation)

这是一个云台控制的软件，我只是实现了上下左右，自动几个功能，为了测试用，不过可以调通。(This is a PTZ control software, I just realized vertical and horizontal, automatic several functions, in order to test, but can be transferred through.)