DAQmx Namespace Reference

Classes
class	CDAQmxAnalogInTask
class	CDAQmxAnalogOutTask
class	CDAQmxCounterOutTask
class	CDAQmxDigitalOutTask
class	CDAQmxTask

Functions
bool	CheckError (const int32 &error)
double	PredictSampleRate (const double &_desiredrate, const uint32_t &_nochannels, const double &_refclockrate, const int32 &_mode)
double	CoerceSampleRates (const double &_desiredrate, const uint32_t &_nochannelsin, const uint32_t &_nochannelsout, const double &_refclockrate)
std::wstring	ClockString (const scope::DaqTimingHelper::Mode &_timing, const std::wstring &_externalclocksource)

Detailed Description

This is basically a C++ wrapper around NI's DAQmx C library.

Contains all DAQmx related stuff.

Function Documentation

bool DAQmx::CheckError

(

const int32 &

error

)

Checks return value of NI DAQmx function for error, prints out error information and throws an exception if DAQMX_THROW_EXCEPTION is defined true.

Returns

returns true if an error occured, false if no error

Definition at line 9 of file DAQmxTask.cpp.

double DAQmx::PredictSampleRate	(	const double &	_desiredrate,
		const uint32_t &	_nochannels,
		const double &	_refclockrate,
		const int32 &	_mode
	)

Predicts the actual sampling rate.

The real sample rate for analog in and out operations can differ slightly. Read NI Knowledge Base "How Is the Actual Scan Rate Determined When I Specify the Scan Rate for My Data Acquisition?".
see here: http://digital.ni.com/public.nsf/websearch/5782F1B396474BAF86256A1D00572D6E?OpenDocument
and here: http://digital.ni.com/public.nsf/allkb/4BBE1409700F6CE686256E9200652F6B?OpenDocument
for details of the calculations.
Note that the result of this function does not take into account the maximum sample rate of your device, this can only be looked up in the devices data sheet!!!! For NI-6259: 32 bit AI and AO clocks.

Parameters

[in]	_desiredrate	desired sample rate
[in]	_nochannels	number of channels
[in]	_refclockrate	rate of the reference clock
[in]	_mode	Modes for PredictSampleRate (defined in NIDAQmx.h) DAQmx_Val_AI 10100 // Analog Input DAQmx_Val_AO 10102 // Analog Output

Returns

the actual sampling rate the device will use

Definition at line 23 of file DAQmxTask.cpp.

double DAQmx::CoerceSampleRates	(	const double &	_desiredrate,
		const uint32_t &	_nochannelsin,
		const uint32_t &	_nochannelsout,
		const double &	_refclockrate
	)

Calculates a sampling rate which both analog in and out can comply to.

see here: http://digital.ni.com/public.nsf/websearch/5782F1B396474BAF86256A1D00572D6E?OpenDocument
for an explanation why both rates could be different.
Note that the result of this function does not take into account the maximum sample rate of your device, this can only be looked up in the devices data sheet!!!!

Parameters

[in]	_desiredrate	desired sampling rate (in Hz)
[in]	_nochannelsin	the number of channels in the input task
[in]	_nochannelsout	the number of channels in the output task
[in]	_refclockrate	frequency of the reference clock (in Hz)

Returns

the sampling rate (in Hz) which both input and output can have simultaneously

Definition at line 37 of file DAQmxTask.cpp.

std::wstring DAQmx::ClockString	(	const scope::DaqTimingHelper::Mode &	_timing,
		const std::wstring &	_externalclocksource
	)

Generates a string for the sample clock from daq_timing.

Parameters

_timing	choosen timing mode (onboard, reference clock, external clock)
_externalclocksource	source of an external sample clock

Returns

a string with the correct clock stuff you can provide to ConfigureSampleTiming

Definition at line 46 of file DAQmxTask.cpp.