采用arduino MEGA2560做MODBUS从站，配合Labview或者维伦通HMI上位机主从通信，实现00000（读写线圈），10000（读开关量输入），30001（读模拟量），40001（读写保持寄存器即PWM）(Using arduino MEGA2560 do MODBUS from standing, cooperate with Labview or whalen HMI upper machine Lord from communication, achieve 00000 (read and write coil), 10000 (read switch input), 30001 (read analog), 40001 (namely PWM register, speaking, reading and writing))