void ModbusRtu::processPacket()
{
QMutexLocker lock(&mMutex);
quint8 cs = mCurrentSlave;
if (mCrc != mCrcBuilder.getValue()) {
resetStateEngine();
processPending();
mMutex.unlockInline();
emit errorReceived(CrcError, cs, 0);
return;
}
if ((mFunction & 0x80) != 0) {
quint8 errorCode = static_cast<quint8>(mData[0]);
resetStateEngine();
processPending();
mMutex.unlockInline();
emit errorReceived(Exception, cs, errorCode);
return;
}
if (mState == Function) {
FunctionCode function = mFunction;
resetStateEngine();
processPending();
mMutex.unlockInline();
emit errorReceived(Unsupported, cs, function);
return;
}
FunctionCode function = mFunction;
switch (function) {
case ReadHoldingRegisters:
case ReadInputRegisters:
{
QList<quint16> registers;
for (int i=0; i<mData.length(); i+=2) {
registers.append(toUInt16(mData, i));
}
resetStateEngine();
processPending();
mMutex.unlockInline();
emit readCompleted(function, cs, registers);
return;
}
case WriteSingleRegister:
{
quint16 value = toUInt16(mData, 0);
quint16 startAddress = mStartAddress;
resetStateEngine();
processPending();
mMutex.unlockInline();
emit writeCompleted(function, cs, startAddress, value);
return;
}
default:
break;
}
}
bool VirtualSerialDevice::open(OpenMode mode)
{
Q_ASSERT(QThread::currentThread() == thread());
if (isOpen()) return true;
d->portHandle = CreateFileA(windowsPortName(portName).toAscii(), GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
if (d->portHandle == INVALID_HANDLE_VALUE) {
setErrorString(tr("The port %1 could not be opened: %2").
arg(portName, winErrorMessage(GetLastError())));
return false;
}
DCB commState;
memset(&commState, 0, sizeof(DCB));
commState.DCBlength = sizeof(DCB);
bool ok = GetCommState(d->portHandle, &commState);
if (ok) {
commState.BaudRate = CBR_115200;
commState.fBinary = TRUE;
commState.fParity = FALSE;
commState.fOutxCtsFlow = FALSE;
commState.fOutxDsrFlow = FALSE;
commState.fInX = FALSE;
commState.fOutX = FALSE;
commState.fNull = FALSE;
commState.fAbortOnError = FALSE;
commState.fDsrSensitivity = FALSE;
commState.fDtrControl = DTR_CONTROL_DISABLE;
commState.ByteSize = 8;
commState.Parity = NOPARITY;
commState.StopBits = ONESTOPBIT;
ok = SetCommState(d->portHandle, &commState);
}
if (!ok) {
qWarning("%s setting comm state", qPrintable(winErrorMessage(GetLastError())));
}
// http://msdn.microsoft.com/en-us/library/aa363190(v=vs.85).aspx says this means
// "the read operation is to return immediately with the bytes that have already been received, even if no bytes have been received"
COMMTIMEOUTS timeouts;
timeouts.ReadIntervalTimeout = MAXDWORD;
timeouts.ReadTotalTimeoutMultiplier = 0;
timeouts.ReadTotalTimeoutConstant = 0;
timeouts.WriteTotalTimeoutMultiplier = 0;
timeouts.WriteTotalTimeoutConstant = 0;
SetCommTimeouts(d->portHandle, &timeouts);
d->writeOverlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
d->writeCompleteNotifier = new QWinEventNotifier(d->writeOverlapped.hEvent, this);
connect(d->writeCompleteNotifier, SIGNAL(activated(HANDLE)), this, SLOT(writeCompleted()));
// This is how we implement readyRead notifications
d->commEventOverlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
d->commEventNotifier = new QWinEventNotifier(d->commEventOverlapped.hEvent, this);
connect(d->commEventNotifier, SIGNAL(activated(HANDLE)), this, SLOT(commEventOccurred()));
if (!SetCommMask(d->portHandle, EV_RXCHAR)) {
// What to do?
qWarning("%s: Could not set comm mask, err=%d", Q_FUNC_INFO, (int)GetLastError());
}
bool result = WaitCommEvent(d->portHandle, &d->commEventMask, &d->commEventOverlapped);
Q_ASSERT(result == false); // Can't see how it would make sense to be anything else...
(void)result; // For release build
if (GetLastError() != ERROR_IO_PENDING) {
setErrorString(tr("An error occurred while waiting for read notifications from %1: %2").
arg(portName, winErrorMessage(GetLastError())));
close();
return false;
}
ok = QIODevice::open(mode);
if (!ok) close();
return ok;
}
