Hi, @J-Hilk!

Looks like i found desired method in QModbusDataUnit class docs. Don't know how i missed it being mentioned in List of All Members for QModbusRtuSerialMaster. I guess digging into Qt docs about Modbus was a proper way to solve this :)

QModbusDataUnit::QModbusDataUnit(QModbusDataUnit::RegisterType type, int address, const QVector<quint16> &data)

In my case this will be:

QModbusDataUnit input(QModbusDataUnit::InputRegisters, 3001, data);

Thanks for joining my journey!

Maybe you can override QModbusServer::processRequest() and do all work there.

Thank you very much!
Using the "finished"-signal everything works fine :-)

@tangxinzhou I'm afraid I do not have a solid solutions. I'm running a workaround now.

Let me post it for you:

void connectDevice(bool connect) { if(connect){ switch (mDevice->state()) { case QModbusDevice::ClosingState: case QModbusDevice::ConnectedState: case QModbusDevice::ConnectingState: mDevice->deleteLater(); mDevice = new QModbusRtuSerialMaster(this); setupSignalSlots(); QTimer::singleShot(100,this, [=]{setConnectParamter(m_port,m_paramter);}); break; case QModbusDevice::UnconnectedState: default: if(!mDevice->connectDevice()){ emit signalModbusError(mDevice->errorString()); mDevice->disconnectDevice(); } break; } }else{ stopPoll(); mDevice->disconnectDevice(); QTimer::singleShot(200,this,[=]{checkDisconnected();}); } } void checkDisconnected() { if(mDevice->state() != QModbusDevice::UnconnectedState){ mDevice->deleteLater(); mDevice = new QModbusRtuSerialMaster(this); setupSignalSlots(); } }