SerialPort port = new SerialPort("COM7")

port.BaudRate = ;

port.BaudRate = ;

port.DataBits = ;

port.Parity = Parity.Odd;

port.StopBits = StopBits.One;

port.Open();    

var master = ModbusSerialMaster.CreateRtu(port);

master.Transport.ReadTimeout = ;

//其中transport还有重试次数和重试间隔时间，默认是3和250

//master.Transport.Retries + "  " + master.Transport.WaitToRetryMilliseconds;

 byte slaveID = ;

ushort address = ;

bool[] coils = new bool[];

coils = master.ReadCoils(slaveID, address, );

        private async void AcquireStatus(ModbusSerialMaster master)

        {

            byte slaveID = ;

            ushort address = ;

            bool[] coils=null;

            master.Transport.ReadTimeout = ;

            try {coils=await master.ReadCoilsAsync(slaveID, address, ); }

            catch (Exception ex)

            {

                MessageBox.Show("your value " + "无返回值");

            }

            if (coils != null)

            {

                this.checkBox1.Checked = coils[];

                MessageBox.Show("your value " + coils[]);

            }

        }