type
  EResNotValid = class (Exception);
  EResUnknownCmd = class (Exception);
  EResNotValidLength = class (Exception);
Const
  RESPONSE_TIMEOUT  = Int16(1000);
  CONNECT_TIMEOUT   = Int16(5000);
  RESPONSE_LENGTH   = int8(8);

  //RESPONSE
  RESPONSE = int8(#$52);

  //COMANDO
  COMMAND = int8(#$41);

  //OPERACIONES
  //Mandar Pulso
  PULSE   = int8(#$50);
  //Leer Entradas
  R_IN    = int8(#$45);
  //Leer Salidas
  W_OUT   = int8(#$53);

  //VALOR
  ZERO    = Int8(#$00);

function TDataModule1.sendCommand(comando, operacion,
  valor:Integer; IP:String; Port: Integer): TIdBytes;
var
  IdTCPClientL          : TIdTCPClient;
  WriteBytes, response  : TIdBytes;
begin
  IdTCPClientL := TIdTCPClient.Create(nil);
  IdTCPClientL.Host := IP;
  IdTCPClientL.Port := Port;
//  IdTCPClientL.ConnectTimeout:= CONNECT_TIMEOUT;
  IdTCPClientL.ReadTimeout := RESPONSE_TIMEOUT;
//  IdTCPClientL.BoundPortMin := 49152;
//  IdTCPClientL.BoundPortMax := 49162;

  SetLength(WriteBytes,4);

  WriteBytes[0]:= comando;
  WriteBytes[1]:= operacion;
  WriteBytes[2]:= valor;
  WriteBytes[3]:= ZERO;

  try
    IdTCPClientL.Connect;
    if IdTCPClientL.Connected then
    begin
      IdTCPClientL.IOHandler.Write(WriteBytes);
      if IdTCPClientL.IOHandler.InputBufferIsEmpty then
      begin
        IdTCPClientL.IOHandler.CheckForDataOnSource(1000);
        IdTCPClientL.IOHandler.CheckForDisconnect;
        if IdTCPClientL.IOHandler.InputBufferIsEmpty then Exit;
      end;
      IdTCPClientL.IOHandler.ReadBytes(response, IdTCPClientL.IOHandler.InputBuffer.Size);
      result := response;
    end;
  finally
    IdTCPClientL.Disconnect;
    IdTCPClientL.Free;
  end;
end;

function TDataModule1.requestStatus(IP: String; Port: Integer): TIdBytes;
begin
  result := sendCommand(COMMAND,R_IN,ZERO,IP,Port);
end;

function TDataModule1.ReadIN(received: TIdBytes): Byte;
begin
  if (Length(received) = RESPONSE_LENGTH) then
  begin
    if (received[1] = COMMAND) and (received[0] = RESPONSE) then
    begin
      case received[2] of
        R_IN: begin
          result := received[5];
        end;
        PULSE:begin
          result := received[5];
        end;
        W_OUT:begin
          result := received[5];
        end;
        else
          raise EResUnknownCmd.Create('Unknown Command: '+received[2].ToString+'.');
      end;
    end
    else
      raise EResNotValid.Create('Not a valid response.');
  end
  else
    raise EResNotValidLength.Create('Not a valid size, received length: '+Length(received).ToString);
end;

function TDataModule1.ReadOUT(received: TIdBytes): Byte;
begin
  if (Length(received) = RESPONSE_LENGTH) then
  begin
    if (received[1] = COMMAND) and (received[0] = RESPONSE) then
    begin
      case received[2] of
        R_IN: begin
          //checkIn(received[3]);
          result := received[4];
        end;
        PULSE:begin
          result := received[4];
        end;
        W_OUT:begin
          result := received[4];
        end;
        else
          raise EResUnknownCmd.Create('Unknown Command: '+received[2].ToString+'.');
      end;
    end
    else
      raise EResNotValid.Create('Not a valid response.');
  end
  else
    raise EResNotValidLength.Create('Not a valid size, received length: '+Length(received).ToString);
end;

{
ejemplo:
    var
      bufReceiv : TIdBytes;
      responseIn, responseOut  : Byte;

    //Consulta
    bufReceiv := requestStatus(urlPilona,portPilona);

    //respuesta estado Entradas:
    responseIn  := ReadIN(bufReceiv);

    //respuesta estado Salidas
    responseOut := ReadOUT(bufReceiv);
}