Not reading the serial port data fully using QExserialports readyread of singal slot

[arunkumaraymuo1]

OS:Ubuntu 11
QExtSerialport 1.2 beta


I am creating an application to write an instruction to a device and receive its response from the device. I connected the readyread() singal to onReadyRead() slot. but sometime its getting only the partial data from the device to the onReadyRead() slot.

I am writing *Read to device
and getting
*Read<Values>
P=122
C=0.33
sometime I got only the partial result in my onReadyRead()

I tried event driven and Polling methods.Still the issue exist.How I can completely read the device input in my onReadyRead().
I checked this on putty software also. its working perfectly in there.

my code sample is given below

void Reader::Create()
{
    PortSettings settings = {BAUD19200, DATA_8, PAR_NONE, STOP_1, FLOW_OFF, 20};
    port = new QextSerialPort(m_strPortName, settings, QextSerialPort::EventDriven);
 
    timer = new QTimer(this);
    timer->setInterval(20);
 
 
 
     connect(timer, SIGNAL(timeout()), SLOT(onReadyRead()));
     connect(port, SIGNAL(readyRead()), SLOT(onReadyRead()));
 
    if (!port->isOpen())
    {
       port->setPortName(m_strPortName);
        port->open(QIODevice::ReadWrite);
    }
    else {
     //   port->close();
    }
 
if (port->isOpen() && port->queryMode() == QextSerialPort::Polling)
       timer->start();
    else
        timer->stop();
 
}
 
void Reader::onReadyRead()
{
    if (port->bytesAvailable())
    {
       m_strData= port->readAll();
    }
}

void Reader::Create()
{
    PortSettings settings = {BAUD19200, DATA_8, PAR_NONE, STOP_1, FLOW_OFF, 20};
    port = new QextSerialPort(m_strPortName, settings, QextSerialPort::EventDriven);

    timer = new QTimer(this);
    timer->setInterval(20);

   

     connect(timer, SIGNAL(timeout()), SLOT(onReadyRead()));
     connect(port, SIGNAL(readyRead()), SLOT(onReadyRead()));

    if (!port->isOpen())
    {
       port->setPortName(m_strPortName);
        port->open(QIODevice::ReadWrite);
    }
    else {
     //   port->close();
    }
 
if (port->isOpen() && port->queryMode() == QextSerialPort::Polling)
       timer->start();
    else
        timer->stop();

}

void Reader::onReadyRead()
{
    if (port->bytesAvailable())
    {
       m_strData= port->readAll();
    }
}

To copy to clipboard, switch view to plain text mode 

[wysota]

Your slot will be called again when more data is available.

[Lesiok]

Remember that the slot can be called after the first byte of data.

[arunkumaraymuo1]

How can I get the full data to a string with a single call.

I want to read the full data to a string before next input to the serial device

[wysota]

How can I get the full data to a string with a single call.

You can't. The speed of data transmission over the wire is finite.

I want to read the full data to a string before next input to the serial device

Aggregate incoming data in a buffer and once you detect(*) all of it has arrived, you can start processing it.

*) how to do that depends on your application protocol