采用stm32单片机，运用定时器中断来定时传输，传输协议采用modbus-Using stm32 SCM, use timer interrupt to timer transmission, transmission protocols using modbus

基于STM32F4库函数写的Modbus协议,支持01,03,05,06,15,16功能码.(STM32F4 library function based on the Modbus protocol written in support of 01,03,05,06,15,16 function code.)