Virtual class with methods for performing conversions from integer A2D counts to floating point voltages for each channel of an A2D. More...

#include <A2DConverter.h>

Inheritance diagram for nidas::core::A2DConverter:

[legend]

Public Member Functions
	A2DConverter (int nchan, int ncoefs)

virtual	~A2DConverter ()

int	getMaxNumChannels () const
	Maximum possible number of channels.

int	getNumConfigChannels () const
	One plus the index of the last active channel.

int	getGain (int ichan) const
	Gain of each channel.

void	setGain (int ichan, int val)

int	getBipolar (int ichan) const

void	setBipolar (int ichan, int val)

virtual float	convert (int ichan, float counts) const =0
	Convert a count to a floating point value.

virtual void	set (int ichan, const float *d, int nd)=0
	Set the initial conversion for a channel.

virtual void	get (int ichan, float *d, int nd) const =0

virtual void	setNAN (int ichan)=0

virtual void	setNAN ()=0

void	readCalFile (CalFile *cf, dsm_time_t tt)
	Read records from a CalFile for calibration coefficients with time tags less than or equal to tt, assuming they are in increasingg order in the file.

Protected Attributes
int	_maxNumChannels
	How many channels on the A2D.

int	_numConfigChannels
	A configured channel has a gain > 0.

int	_ncoefs
	Number of coefficients in the conversion.

int *	_gain
	Gain setting of each channel.

int *	_bipolar
	Polarity setting, 1=bi-polar.

Private Member Functions
	A2DConverter (const A2DConverter &x)
	No copy.

A2DConverter &	operator= (const A2DConverter &x)
	No assign.

Detailed Description

Virtual class with methods for performing conversions from integer A2D counts to floating point voltages for each channel of an A2D.

Two subclasses are defined, LinearA2DConverter and PolyA2DConverter. A2D sensor classes instantiate whichever type they want to use.

The gain and bipolar value for each channel in the A2DConverter are set by the A2D sensor, typically at configuration time in the validate() method. A gain of 0 indicates that a channel is not used.

Our A2Ds (DSMAnalogSensor, DSC_A2DSensor, A2D_Serial) typically instantiate two converters. A LinearA2DConverter is used to convert counts to approximate voltages using the known voltage transformations of the A2D, at a given gain and bipolar value for each channel.

A second converter, often a 3rd order PolyA2DConverter, then applies corrections to obtain a calibrated voltage.

If an A2D CalFile has been configured for the sensor, the readCalFile() method of the second converter can be called to read the conversion coefficients from the file. See the doc for the readCalFile() method for information about the number of expected values in the calibration file.

Constructor & Destructor Documentation

◆ A2DConverter() [1/2]

A2DConverter::A2DConverter	(	int	nchan,
		int	ncoefs )

References _bipolar, _gain, and nidas::core::getSample().

◆ ~A2DConverter()

A2DConverter::~A2DConverter ( )

virtual

References _bipolar, and _gain.

◆ A2DConverter() [2/2]

nidas::core::A2DConverter::A2DConverter ( const A2DConverter & x )

private

No copy.

Member Function Documentation

◆ convert()

virtual float nidas::core::A2DConverter::convert	(	int	ichan,
		float	counts ) const

pure virtual

Convert a count to a floating point value.

Implemented in nidas::core::LinearA2DConverter, and nidas::core::PolyA2DConverter.

Referenced by nidas::dynld::raf::A2D_Serial::process().

◆ get()

virtual void nidas::core::A2DConverter::get	(	int	ichan,
		float *	d,
		int	nd ) const

pure virtual

Implemented in nidas::core::LinearA2DConverter, and nidas::core::PolyA2DConverter.

Referenced by nidas::dynld::raf::A2D_Serial::dumpConfig().

◆ getBipolar()

int A2DConverter::getBipolar ( int ichan ) const

References _bipolar, _maxNumChannels, and nidas::core::getSample().

Referenced by nidas::dynld::raf::A2D_Serial::getBipolar().

◆ getGain()

int A2DConverter::getGain ( int ichan ) const

Gain of each channel.

An A2DConverter needs to know the gain and bipolarity because it reads the cal file and there are typically cal records for each gain and polarity.

References _gain, _maxNumChannels, and nidas::core::getSample().

Referenced by nidas::dynld::raf::A2D_Serial::getGain().

◆ getMaxNumChannels()

int nidas::core::A2DConverter::getMaxNumChannels ( ) const

inline

Maximum possible number of channels.

References _maxNumChannels.

◆ getNumConfigChannels()

int nidas::core::A2DConverter::getNumConfigChannels ( ) const

inline

One plus the index of the last active channel.

An active channel has a gain > 0.

References _numConfigChannels.

Referenced by readCalFile().

◆ operator=()

A2DConverter & nidas::core::A2DConverter::operator= ( const A2DConverter & x )

private

No assign.

◆ readCalFile()

void A2DConverter::readCalFile	(	CalFile *	cf,
		dsm_time_t	tt )

Read records from a CalFile for calibration coefficients with time tags less than or equal to tt, assuming they are in increasingg order in the file.

Each record has a gain and bipolar value after the time, followed by coefficients for each channel.

A calibration record is used for a channel if its gain and bipolar fields match the values for the configured channel. A gain value of -1 in the file is a wildcard, matching any configured gain for a channel, and likewise for the bipolar value.

readCalFile() expects there to be getNumConfigChannels() X _ncoefs number of coefficients after the time, gain and bipolar fields in each CalFile record. If there are less than the expected number, a warning is logged, and missing coefficients are set to floatNAN.

Exceptions

EOFException, IOException, ParseException

References _bipolar, _gain, _ncoefs, getNumConfigChannels(), nidas::core::getSample(), LOG_WARNING, set(), and setNAN().

Referenced by nidas::dynld::raf::A2D_Serial::process().