diff options
Diffstat (limited to 'src/serialbus/qmodbusrtuserialslave_p.h')
| -rw-r--r-- | src/serialbus/qmodbusrtuserialslave_p.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/serialbus/qmodbusrtuserialslave_p.h b/src/serialbus/qmodbusrtuserialslave_p.h index 99f1a4a..70f28cd 100644 --- a/src/serialbus/qmodbusrtuserialslave_p.h +++ b/src/serialbus/qmodbusrtuserialslave_p.h @@ -39,7 +39,9 @@ #include <QtCore/qbytearray.h> #include <QtCore/qdebug.h> +#include <QtCore/qelapsedtimer.h> #include <QtCore/qloggingcategory.h> +#include <QtCore/qmath.h> #include <QtSerialBus/qmodbusrtuserialslave.h> #include <QtSerialPort/qserialport.h> @@ -73,6 +75,21 @@ public: m_serialPort = new QSerialPort(q); QObject::connect(m_serialPort, &QSerialPort::readyRead, [this]() { + + if (m_interFrameTimer.isValid() + && m_interFrameTimer.elapsed() > m_interFrameDelayMilliseconds + && !m_requestBuffer.isEmpty()) { + // This permits response buffer clearing if it contains garbage + // but still permits cases where very slow baud rates can cause + // chunked and delayed packets + qCDebug(QT_MODBUS_LOW) << "(RTU server) Dropping older ADU fragments due to larger than 3.5 char delay (expected:" + << m_interFrameDelayMilliseconds << ", max:" + << m_interFrameTimer.elapsed() << ")"; + m_requestBuffer.clear(); + } + + m_interFrameTimer.start(); + const qint64 size = m_serialPort->size(); m_requestBuffer += m_serialPort->read(size); @@ -330,12 +347,19 @@ public: m_serialPort->setStopBits(m_stopBits); } + // for calulcation details see + // QModbusRtuSerialMasterPrivate::calculateInterFrameDelay() + m_interFrameDelayMilliseconds = qMax(m_interFrameDelayMilliseconds, + qCeil(3500. / (qreal(m_baudRate) / 11.))); + m_requestBuffer.clear(); } QByteArray m_requestBuffer; bool m_processesBroadcast = false; QSerialPort *m_serialPort = nullptr; + QElapsedTimer m_interFrameTimer; + int m_interFrameDelayMilliseconds = 2; }; QT_END_NAMESPACE |