vc程序与modbus进行通讯源码， 可以与plc控制的下位机通讯，可以了解到通讯编码规则-vc program source code to communicate with modbus, plc control with the next bit machine communications, coding rules can understand communication

windows/linux 多平台通用modbus网关源代码，通过master模式收集数据，再通过slave模式传送出去。支持modbus rtu，moudbus tcp。-windows/linux multi-platform modbus gateway source code. data collected through the master mode, and then sent through the slave mode. Support modbus rtu, moudbus

modbus rtu in vb.Read and write plc registers and coils using this source code.

VC6源码，用于计算Modbus帧校验和。-source code for calculating Modbus CRC value. source code is for Visual C++