/// <summary>
/// This function gets message from the remote unit.
/// </summary>
/// <param name="Rxmsg">Received message</param>
/// <param name="Txmsg">Transmited message, information about this frmae could be necessary to properly init received frame.
/// </param>
/// <returns>
/// ALRes_Success: Operation accomplished successfully
/// ALRes_DatTransferErrr: Data transfer is imposible because of a communication error – loss of
/// communication with a station
/// ALRes_DisInd: Disconnect indication – connection has been shut down remotely or lost because of
/// communication error. Data is unavailable
/// </returns>
protected override AL_ReadData_Result GetMessage(out ModBusMessage Rxmsg, ModBusMessage Txmsg)
{
Rxmsg = null;
try
{
InterCharStopwatch.Reset();
InterCharStopwatch.Start();
if (!CheckCharTimeout(GetProtocolParameters.ResponseTimeOutSpan, InterCharStopwatch))
{
GetIProtocolParent.IncStRxNoResponseCounter();
return(AL_ReadData_Result.ALRes_DatTransferErrr);
}
GetIProtocolParent.TimeMaxResponseDelayAdd(InterCharStopwatch.ElapsedMilliseconds);
Rxmsg = m_Pool.GetEmptyISesDBuffer();
Rxmsg.userDataLength = Rxmsg.userBuffLength;
Rxmsg.offset = 0;
bool first = true;
do
{
byte lastChar;
InterCharStopwatch.Reset();
InterCharStopwatch.Start();
switch (GetICommunicationLayer.GetChar(out lastChar))
{
case TGetCharRes.Success:
if (!Rxmsg.WriteByte(lastChar))
{
return(AL_ReadData_Result.ALRes_DatTransferErrr);
}
if (first)
{
first = false;
}
else
{
GetIProtocolParent.TimeCharGapAdd(CAS.Lib.RTLib.Processes.Timer.ToUSeconds(InterCharStopwatch.Elapsed));
}
break;
case TGetCharRes.DisInd:
return(AL_ReadData_Result.ALRes_DisInd);
}
}while (CheckCharTimeout(((ModBus_ProtocolParameters)GetProtocolParameters).TimeoutCharacterSpan, InterCharStopwatch));
Rxmsg.userDataLength = Rxmsg.offset;
Rxmsg.offset = 0;
if (CheckCharTimeout(((ModBus_ProtocolParameters)GetProtocolParameters).TimeoutCharacterSpan, InterCharStopwatch))
{
Flush(((ModBus_ProtocolParameters)GetProtocolParameters).InterframeGapSpan);
Rxmsg.ReturnEmptyEnvelope();
Rxmsg = null;
GetIProtocolParent.IncStRxFragmentedCounter();
return(AL_ReadData_Result.ALRes_DatTransferErrr);
}
return(AL_ReadData_Result.ALRes_Success);
}
catch (DisconnectException) { return(AL_ReadData_Result.ALRes_DisInd); }
}
/// <summary>
/// This function gets message from the remote unit.
/// </summary>
/// <param name="receiveMessage">Received message</param>
/// <param name="transmitMessage">Transited message, information about this frame could be necessary to properly initialize received frame.
/// </param>
/// <returns>
/// ALRes_Success: Operation accomplished successfully
/// ALRes_DatTransferErrr: Data transfer is imposable because of a communication error – loss of
/// communication with a station
/// ALRes_DisInd: Disconnect indication – connection has been shut down remotely or lost because of
/// communication error. Data is unavailable
/// </returns>
protected override AL_ReadData_Result GetMessage(out ModBusMessage receiveMessage, ModBusMessage transmitMessage)
{
receiveMessage = null;
try
{
InterCharStopwatch.Reset();
InterCharStopwatch.Start();
if (!CheckCharTimeout(GetProtocolParameters.ResponseTimeOutSpan, InterCharStopwatch))
{
GetIProtocolParent.IncStRxNoResponseCounter();
return(AL_ReadData_Result.ALRes_DatTransferErrr);
}
GetIProtocolParent.TimeMaxResponseDelayAdd(InterCharStopwatch.ElapsedMilliseconds);
receiveMessage = m_Pool.GetEmptyISesDBuffer();
receiveMessage.userDataLength = receiveMessage.userBuffLength;
receiveMessage.offset = 0;
bool first = true;
do
{
byte lastChar;
InterCharStopwatch.Reset();
InterCharStopwatch.Start();
switch (GetICommunicationLayer.GetChar(out lastChar))
{
case TGetCharRes.Success:
if (!receiveMessage.WriteByte(lastChar))
{
AssemblyTraceEvent.Tracer.TraceEvent(TraceEventType.Warning, 77, "ModBusProtocol.GetMessage: cannot write character received from the Communication Layer");
return(AL_ReadData_Result.ALRes_DatTransferErrr);
}
if (first)
{
first = false;
}
else
{
GetIProtocolParent.TimeCharGapAdd(CAS.Lib.RTLib.Processes.Timer.ToUSeconds(InterCharStopwatch.Elapsed));
}
break;
case TGetCharRes.DisInd:
return(AL_ReadData_Result.ALRes_DisInd);
}
}while (CheckCharTimeout(((ModBus_ProtocolParameters)GetProtocolParameters).Timeout15Span, InterCharStopwatch));
receiveMessage.userDataLength = receiveMessage.offset;
receiveMessage.offset = 0;
if (CheckCharTimeout(((ModBus_ProtocolParameters)GetProtocolParameters).Timeout35Span, InterCharStopwatch))
{
Flush(((ModBus_ProtocolParameters)GetProtocolParameters).Timeout35Span);
receiveMessage.ReturnEmptyEnvelope();
receiveMessage = null;
GetIProtocolParent.IncStRxFragmentedCounter();
return(AL_ReadData_Result.ALRes_DatTransferErrr);
}
return(AL_ReadData_Result.ALRes_Success);
}
catch (DisconnectException)
{
return(AL_ReadData_Result.ALRes_DisInd);
}
}
