internal int RequestBytesToRead(byte[] frameStart)
{
byte functionCode = frameStart[1];
IModbusFunctionService service = ModbusFactory.GetFunctionServiceOrThrow(functionCode);
return(service.GetRtuRequestBytesToRead(frameStart));
}
internal int ResponseBytesToRead(byte[] frameStart)
{
byte functionCode = frameStart[1];
if (functionCode > Modbus.ExceptionOffset)
{
return(1);
}
IModbusFunctionService service = ModbusFactory.GetFunctionServiceOrThrow(functionCode);
return(service.GetRtuResponseBytesToRead(frameStart));
}
public static IModbusFunctionService GetFunctionServiceOrThrow(this IModbusFactory factory, byte functionCode)
{
IModbusFunctionService service = factory.GetFunctionService(functionCode);
if (service == null)
{
string msg = $"Function code {functionCode} not supported.";
factory.Logger.Warning(msg);
throw new NotImplementedException(msg);
}
return(service);
}
public IModbusMessage ApplyRequest(IModbusMessage request)
{
IModbusMessage response;
try
{
//Try to get a handler for this function.
IModbusFunctionService handler = _handlers.GetValueOrDefault(request.FunctionCode);
//Check to see if we found a handler for this function code.
if (handler == null)
{
throw new InvalidModbusRequestException(SlaveExceptionCodes.IllegalFunction);
}
//Process the request
response = handler.HandleSlaveRequest(request, DataStore);
}
catch (InvalidModbusRequestException ex)
{
// Catches the exception for an illegal function or a custom exception from the ModbusSlaveRequestReceived event.
response = new SlaveExceptionResponse(
request.SlaveAddress,
(byte)(Modbus.ExceptionOffset + request.FunctionCode),
ex.ExceptionCode);
}
#if NET45 || NET46
catch (Exception ex)
{
//Okay - this is no beuno.
response = new SlaveExceptionResponse(request.SlaveAddress,
(byte)(Modbus.ExceptionOffset + request.FunctionCode),
SlaveExceptionCodes.SlaveDeviceFailure);
//Give the consumer a chance at seeing what the *(&& happened.
Trace.WriteLine(ex.ToString());
}
#else
catch (Exception)
{
//Okay - this is no beuno.
response = new SlaveExceptionResponse(request.SlaveAddress,
(byte)(Modbus.ExceptionOffset + request.FunctionCode),
SlaveExceptionCodes.SlaveDeviceFailure);
}
#endif
return(response);
}
internal int RequestBytesToRead(byte[] frameStart)
{
byte functionCode = frameStart[1];
IModbusFunctionService service = _modbusFactory.GetFunctionService(functionCode);
if (service == null)
{
string msg = $"Function code {functionCode} not supported.";
Logger.Warning(msg);
throw new NotImplementedException(msg);
}
return(service.GetRtuRequestBytesToRead(frameStart));
}
/// <summary>
/// Simple Modbus serial RTU slave example.
/// </summary>
public static async Task StartModbusSerialRtuSlaveWithCustomMessage(CancellationToken cancellationToken)
{
using (SerialPort slavePort = new SerialPort(PrimarySerialPortName))
{
// configure serial port
slavePort.BaudRate = 57600;
slavePort.DataBits = 8;
slavePort.Parity = Parity.Even;
slavePort.StopBits = StopBits.One;
slavePort.Open();
var adapter = new SerialPortAdapter(slavePort);
var functionServices = new IModbusFunctionService[]
{
new HmiBufferFunctionService()
};
var factory = new ModbusFactory(functionServices, true, new ConsoleModbusLogger(LoggingLevel.Debug));
// create modbus slave
var slaveNetwork = factory.CreateRtuSlaveNetwork(adapter);
var acTechDataStore = new SlaveStorage();
acTechDataStore.InputRegisters.StorageOperationOccurred += (sender, args) => Console.WriteLine($"ACTECH Input registers: {args.Operation} starting at {args.StartingAddress}");
acTechDataStore.HoldingRegisters.StorageOperationOccurred += (sender, args) => Console.WriteLine($"ACTECH Holding registers: {args.Operation} starting at {args.StartingAddress}");
var danfossStore = new SlaveStorage();
danfossStore.InputRegisters.StorageOperationOccurred += (sender, args) => Console.WriteLine($"DANFOSS Input registers: {args.Operation} starting at {args.StartingAddress}");
danfossStore.HoldingRegisters.StorageOperationOccurred += (sender, args) => Console.WriteLine($"DANFOSS Holding registers: {args.Operation} starting at {args.StartingAddress}");
IModbusSlave actechSlave = factory.CreateSlave(21, acTechDataStore);
IModbusSlave danfossSlave = factory.CreateSlave(1, danfossStore);
slaveNetwork.AddSlave(actechSlave);
slaveNetwork.AddSlave(danfossSlave);
await slaveNetwork.ListenAsync(cancellationToken);
}
}