Fetching Data Fails with Timeout Error After 250k Values in Qt VISA Connection

Question

I'm currently working on integrating a VISA connection into my Qt application to interact with a device for various tasks such as setting parameters like voltage and sample rate, starting data recording, fetching data, and returning the data. Most functionalities are implemented and working as expected; however, I encounter an issue when attempting to fetch data: after successfully receiving 250,000 values, I no longer receive any data, and a timeout error is triggered, specifically "Timeout Expired Before Operation Completed", as indicated by the condition if (status < VI_SUCCESS).

Has anyone experienced a similar issue or noticed any potential mistakes in my approach that could lead to this problem?

QString GetData() {
    ViStatus status = VI_SUCCESS;
    ViUInt32 returnCount = 0;
    ViSession rmHandle, scopeHandle;
    char idnResponse[5000];
    vector<float> allData;

    const char resourceString1[] = "USB Connection string";

    // Open Resource manager first
    status = viOpenDefaultRM(&rmHandle);
    status = viOpen(rmHandle, resourceString1, VI_NULL, VI_NULL, &scopeHandle);
    QElapsedTimer timer;

    status = viClear(scopeHandle); //clear instrument's io buffers
    QString command = "FLOG:DATA?";
    QByteArray startMeasurementbyteArray = command.toUtf8();
    QByteArray byteArray = command.toUtf8();
    const char* cStartCommand = startMeasurementbyteArray.constData();
    const char* cCommand = byteArray.constData();
    QString allValues = "<br>";

    bool firstRead = true;

    uint8_t leftoverBytes[3];
    uint8_t leftoverByteLength = 0;
    timer.start();
    bool weHaveData = true;
    while(timer.elapsed() <= 300000)
    {
        status = viWrite(scopeHandle, (ViBuf)cCommand, (ViUInt32)strlen(cCommand), &returnCount);
        status = viRead(scopeHandle, (ViBuf)idnResponse, sizeof(idnResponse), &returnCount);
        // idnResponse[returnCount] = '\0'; //terminate the string properly
        if (status < VI_SUCCESS)
        {
            char statusStr[100];
            viStatusDesc(scopeHandle, status, statusStr);
            TRACE(TL_WARN, statusStr);
            weHaveData = false;
            // break;
        }
        if(weHaveData)
        {
            int dataOffset = 0;
            if (firstRead)
            {
                if (idnResponse[0] != '#') break;
                dataOffset = (int)idnResponse[1] - '0' + 2; // skip length of length
                firstRead = false;
            }

            if (leftoverByteLength)
            {
                float val;
                memcpy(&val, leftoverBytes, leftoverByteLength);
                memcpy(((uint8_t*)&val)+leftoverByteLength, idnResponse, sizeof(float)-leftoverByteLength);
                allData.push_back(val);
                dataOffset = sizeof(float)-leftoverByteLength;
            }

            leftoverByteLength = (returnCount - dataOffset) % sizeof(float);

            // Convert the binary data to a float array and return it as a QString
            size_t oldSize = allData.size();
            allData.resize(oldSize + (returnCount - dataOffset)/sizeof(float));
            memcpy(allData.data() + oldSize, idnResponse + dataOffset, returnCount - dataOffset - leftoverByteLength);

            // rest goes to leftover buffer
            memcpy(leftoverBytes, idnResponse + sizeof(idnResponse)-leftoverByteLength, leftoverByteLength);

        }
        weHaveData = true;
        //Just debug stuff
        if(allData.size() >= 250000){
            TRACE(TL_WARN,"Why dont you continue");
            status = viWrite(scopeHandle, (ViBuf)cCommand, (ViUInt32)strlen(cCommand), &returnCount);
        }


        // QThread::msleep(10);
    }




    return "All Values recorded: "+ QString::number(allData.size());
}