能解释下，内容mudbus通讯介绍吗，不是很懂

def ReadRegister(self,MasterNumber,Address,Lenth):
    self.ReadError = 0
    if Address.isdigit() and Lenth.isdigit():
        if (int(Address) != 0) and (int(Lenth) != 0):
            try:
                Value = self.InterverLink[MasterNumber].execute(1, 0x04, int(Address) - 1, int(Lenth))
                time.sleep(0.1)
                return Value
            except InsCAR.ModbusErrorType:
                self.ReadError = 1
                if self.MachineTestResultList[MasterNumber][0] == 1:
                    self.MachineTestResultList[MasterNumber][0] = 4
                self.InformationUpdate.emit(str(MasterNumber + 1) + "号逆变器通信异常", 2, self.MachineTestResultList)
                return [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
        else:
            self.ReadError = 2
            if self.MachineTestResultList[MasterNumber][0] == 1:
                self.MachineTestResultList[MasterNumber][0] = 4
            self.InformationUpdate.emit("工程脚本文件数据格式错误", 2, self.MachineTestResultList)
            return [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
    else:
        self.ReadError = 2
        if self.MachineTestResultList[MasterNumber][0] == 1:
            self.MachineTestResultList[MasterNumber][0] = 4
        self.InformationUpdate.emit("工程脚本文件数据格式错误", 2, self.MachineTestResultList)
        return [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]