protected override void Decode(IChannelHandlerContext context, IByteBuffer input, List <object> output)
{
//Transaction Identifier + Protocol Identifier + Length + Unit Identifier + Function Code
if (input.Capacity < 2 + 2 + 2 + 1 + 1)
{
return;
}
ModbusHeader header = new ModbusHeader(input);
short functionCode = input.ReadByte();
ModbusFunction function = null;
if (Enum.IsDefined(typeof(ModbusCommand), functionCode))
{
var command = Enum.GetName(typeof(ModbusCommand), functionCode);
function = (ModbusFunction)Activator.CreateInstance(Type.GetType(string.Format(typeName, isServerMode ? "Request" : "Response", command)));
}
if (functionCode >= maxFunctionCode)
{
function = new ExceptionFunction(functionCode);
}
else if (function == null)
{
function = new ExceptionFunction(functionCode, 0x01);
}
function.Decode(input);
ModbusFrame frame = new ModbusFrame(header, function);
output.Add(frame);
}
/// <summary>
/// This Task handles all the types of Modbus Functions
/// </summary>
/// <returns>The operation.</returns>
/// <param name="functionType">Function type.</param>
/// <param name="slaveAddress">Slave address.</param>
/// <param name="nrRegisters">Nr registers.</param>
/// <param name="selectedRegisterAddress">Selected register address.</param>
/// <param name="dataToWrite">Data to write.</param>
public async Task <ReceivedData> ModbusOperation(ModbusFunctionType functionType, byte slaveAddress, byte[] nrRegisters, byte[] selectedRegisterAddress, byte[] dataToWrite)
{
frameToSend = new ModbusFrame();
if (functionType == ModbusFunctionType.WriteCoil || functionType == ModbusFunctionType.WriteHoldingRegister)
{
frameToSend = new ModbusFrame(slaveAddress, functionType, selectedRegisterAddress, null, dataToWrite);
}
else
{
frameToSend = new ModbusFrame(slaveAddress, functionType, selectedRegisterAddress, nrRegisters, null);
}
//We send the message to the Slave Device
TransmissionState b = await SendMessage(frameToSend.BytePacketToSend);
sizeOfMessage = CalculateExpectedSize();
ReceivedData responseData = new ReceivedData();
//If the message was transmitted right, then proceed with the listening
//of the response
if (b == TransmissionState.OK)
{
System.Diagnostics.Debug.WriteLine("MessageSended: " + b.ToString());
//TO-DO Implement the retry mechanism
//int retries = 3;
//responseData = await ListenMessages();
responseData = await ListenMessages();
}
else
{
responseData.state = TransmissionState.ErrorSendMessage;
}
if (responseData.state == TransmissionState.OK)
{
frameReceived = new ModbusFrame(responseData.data);
}
else
{
frameReceived = new ModbusFrame();
}
return(responseData);
}
public ushort CallModbusFunction(ModbusFunction function)
{
if (ConnectionState.Connected != connectionState || Channel == null)
{
throw new Exception("Not connected!");
}
SetTransactionIdentifier();
ModbusHeader header = new ModbusHeader(transactionIdentifier, UnitIdentifier);
ModbusFrame frame = new ModbusFrame(header, function);
Channel.WriteAndFlushAsync(frame);
return(transactionIdentifier);
}
