Hello,
I am trying to solve a mystery. I have a PCI 6220 board installed in a linux PC running OpenSUSE 12.2. When I compile and run my test program and try to read in samples the DAQmxBaseReadAnalogF64 returns 0 for success but a samplecount of 0.
If I install the card in a Windows 7 PC using DAQmx (nor base) everything runs perfectly and I get samples as expected.
I also tried the NI example programs, but these also return no samples.
My assumption was NI drivers, so I tried to uninstall and reinstall the drivers, rebooted and then tried again - Same result.
Have I missed something obvious or any suggestions?
The basic source code as follows:
bool
do_initialise()
{
XString s;
m_nchannels = 16;
m_device = "Dev1";
m_maxSampleValue = 10.0;
m_sampleRate = 8000;
m_samplesPerCallback = m_sampleRate / 10;
m_dataBufSize = m_nchannels * m_samplesPerCallback;
float64 *pFloatBuf=new float64[m_dataBufSize];
m_databuf = pFloatBuf;
return true;
}
bool
do_open()
{
m_openflag = false;
x_int32_t r=0;
r = DAQmxBaseCreateTask("", (TaskHandle *)&m_handle);
if (r >= 0)
{
for (int i=0;i<m_nchannels;i++)
{
XString channelname;
channelname.format("%s/ai%d", m_device.c_str(), i);
r = DAQmxBaseCreateAIVoltageChan((TaskHandle)m_handle,
channelname,
"",
DAQmx_Val_RSE,
-m_maxSampleValue,
m_maxSampleValue,
DAQmx_Val_Volts,
NULL);
if (r < 0)
{
// log error
}
}
}
else
{
// log error
}
if (r >= 0)
{
// Our output blocks are in 1/10th second
// Out input frequency is fixed at 8000Hz
// So request 800 samples!
r = DAQmxBaseCfgSampClkTiming((TaskHandle)m_handle, "", 8000.0, DAQmx_Val_Rising, DAQmx_Val_ContSamps, m_samplesPerCallback * m_nchannels * 10);
if (r < 0)
{
// log error
}
}
if (r >= 0)
{
r = DAQmxBaseStartTask((TaskHandle)m_handle);
if (r < 0)
{
// log error
}
}
if (r >= 0)
{
m_openflag = true;
}
else
{
DAQmxBaseStopTask((TaskHandle)m_handle);
DAQmxBaseClearTask((TaskHandle)m_handle);
}
return m_openflag;
}
bool
do_close()
{
DAQmxBaseStopTask((TaskHandle)m_handle);
DAQmxBaseClearTask((TaskHandle)m_handle);
m_openflag = false;
return true;
}
bool
do_onDataReady()
{
float64 *data=(float64 *)m_databuf;
int32 samplesread=0;
int r;
r = DAQmxBaseReadAnalogF64((TaskHandle)m_handle, m_samplesPerCallback, 10.0, DAQmx_Val_GroupByChannel, data, m_dataBufSize, &samplesread, NULL);
theAppLog.debug("After DAQmxReadAnalogF64 r=%d, samplesread=%d", r, samplesread);
return true;
}
int
main()
{
bool ok=true;
if (ok) ok = do_initialise();
if (ok) ok = do_open();
for (int i=0;ok&&i<100;i++)
{
ok = do_onDataReady();
}
if (ok) ok = do_close();
do_shutdown();
}
