A class that represent a stream of numerical data, a signal. More...

#include <QDaqChannel.h>

Inheritance diagram for QDaqChannel:

Collaboration diagram for QDaqChannel:

Public Types
enum	ChannelType { Normal, Clock, Random, Inc, Dec }
	Type of the channel. More...

enum	AveragingType { None, Running, Delta, ForgettingFactor, Median }
	Type of channel averaging. More...

enum	NumberFormat { General, FixedPoint, Scientific, Time }
	Type of format for textual representation of channel data. More...

Public Slots
void	push (double v)
	Insert a value into the channel. More...

void	clear ()
	Clear internal channel memory. More...

double	value () const
	Get the current channel value. More...

double	std () const
	Get the current channel value standard deviation. More...

Public Slots inherited from QDaqObject
QString	errorBacktrace (int maxItems=10) const
	Print a backtrace of recent errors in this QDaqObject.

QString	path () const
	Return the object's path in the QDaq tree. More...

QString	objectTree () const
	Output in a string the object hierarchy beneath this object.

QString	listProperties () const
	List the objects properties.

QString	listFunctions () const
	List the objects scriptable functions.

QDaqObject *	parent () const

QDaqObjectList	children () const
	Return a list of children of this object.

bool	hasChildren () const
	Returns true if the object has children.

QDaqObject *	appendChild (QDaqObject *obj)
	Adds a new child QDaqObject, as the last child and returns a pointer to it.

QDaqObject *	insertBefore (QDaqObject newobj, QDaqObject existingobj)
	Adds a new child QDaqObject, before an existing child and returns a pointer to it.

QDaqObject *	clone ()
	Clone a QDaqObject with its child objects.

QDaqObject *	removeChild (QDaqObject *obj)
	Remove a child and return a pointer to it.

QDaqObject *	replaceChild (QDaqObject newobj, QDaqObject oldobj)
	Replace a child and return a pointer to the old child.

QDaqObject *	findChild (const QString &name) const
	Find the first child QDaqObject with objectName equal to name.

Public Member Functions
virtual void	detach ()
	Detach this QDaqObject from the QDaq tree. More...

virtual QString	formatedValue ()
	Returns the channel value formatted according to format/digits.

Public Member Functions inherited from QDaqJob
Q_INVOKABLE	QDaqJob (const QString &name)
	QDaqJob constructor. More...

virtual void	attach ()
	Attach this QDaqObject to the QDaq tree. More...

QDaqLoop *	topLoop () const
	Returns the top level loop that this job belongs to.

QDaqLoop *	loop () const
	Returns the loop that this job belongs to.

virtual QDaqScriptEngine *	loopEngine () const
	Returns the QDaqScriptEngine of the top level loop.

Public Member Functions inherited from QDaqObject
Q_INVOKABLE	QDaqObject (const QString &name)
	Construct a QDaqObject with a name. More...

bool	isAttached () const
	Returns true is this object is attached to the QDaq tree.

Protected Member Functions
virtual bool	arm_ ()
	Performs internal initialization for the job. More...

virtual bool	run ()
	Perform channel tasks. More...

Protected Member Functions inherited from QDaqJob
virtual void	disarm_ ()
	Performs internal de-initialization. More...

bool	setArmed (bool on)
	Arms or disarms a job. More...

virtual bool	exec ()
	Called when the job is executed. More...

Protected Member Functions inherited from QDaqObject
void	pushError (const QString &type, const QString &descr=QString()) const
	Push an error in the error queue.

void	throwScriptError (const QString &msg) const
	Throw a script error with message msg.

bool	checkName (const QString &name) const
	Check if name is a legal name for an QDaqObject. More...

virtual void	writeh5 (H5::Group g, QDaqH5File f) const
	Write contents of the object to a H5 group. More...

virtual void	readh5 (H5::Group g, QDaqH5File f)
	Read contents of the object from a H5 group. More...

Properties
ChannelType	type
	Type of the channel.

QString	signalName
	User supplied signal name. More...

QString	unit
	User supplied unit of measurement. More...

NumberFormat	format
	Option for formatting channel data for textual representation. More...

int	digits
	Number of decimal digits to display. More...

QDaqVector	range
	Signal range. More...

double	offset
	Channel offset. More...

double	multiplier
	Channel multiplier. More...

AveragingType	averaging
	Type of on-line averaging.

double	forgettingFactor
	Forgetting factor value. More...

uint	depth
	Averaging depth. More...

uint	memsize
	Channel memory used. More...

bool	dataReady
	True if valid data exist on the channel. More...

QString	parserExpression
	muParser Expression. More...

Properties inherited from QDaqJob
bool	armed
	True if job is armed. More...

QString	runCode
	Script code executed by the job at each repetition. More...

QString	armCode
	Script code executed by the job in the arming face. More...

QString	disarmCode
	Script code executed by the job in the dis-arming face. More...

Additional Inherited Members
Signals inherited from QDaqObject
void	propertiesChanged ()
	Fired when object properties have changed.

void	updateWidgets ()
	Fired when widgets need update.

Static Public Member Functions inherited from QDaqObject
static QDaqRoot *	root ()
	Obtain a pointer to the one-and-only QDaqRoot object.

static QDaqObject *	fromPath (const QString &path)
	Return a pointer to an object given its full path in the QDaq tree. More...

Public Attributes inherited from QDaqObject
QMutex	comm_lock
	A recursive mutex for synching thread access to this object.

Detailed Description

A class that represent a stream of numerical data, a signal.

Real time data is handeled in QDaq through the QDaqChannel class. E.g., an instrument provides measurement data through QDaqChannel objects.

QDaqChannel provides tools for displaying, transforming, averaging the data of the channel.

Definition at line 28 of file QDaqChannel.h.

Member Enumeration Documentation

enum QDaqChannel::AveragingType

Type of channel averaging.

Enumerator
None	No averaging.
Running	Running (box) averaging.
Delta	Running average for signals of alternating sign.
ForgettingFactor	Running average with forgetting (exponential weighting).
Median	Running median filter.

Definition at line 104 of file QDaqChannel.h.

enum QDaqChannel::ChannelType

Type of the channel.

Enumerator
Normal	Normal channel - nothing special.
Clock	Records time in each repetition. Can be used for time measurement.
Random	Generates random samples.
Inc	Starting from an initial value increments by 1 in each repetition.
Dec	Starting from an initial value decrements by 1 in each repetition.

Definition at line 93 of file QDaqChannel.h.

enum QDaqChannel::NumberFormat

Type of format for textual representation of channel data.

Enumerator
General	No special formating.
FixedPoint	No special formating.
Scientific	No special formating.
Time	No special formating.

Definition at line 115 of file QDaqChannel.h.

Member Function Documentation

bool QDaqChannel::arm_ ( )

protectedvirtual

Performs internal initialization for the job.

It is called by the setArmed() function.

This function can be reimplemented to perform specific initialization for a job. The parent class arm_() function should be called afterwards.

In the default implementation, if a loopEngine() exists the script code is checked against the script engine for errors.

If initialization is sucessfull it returns true, otherwise the function returns false.

Reimplemented from QDaqJob.

Definition at line 130 of file QDaqChannel.cpp.

void QDaqChannel::clear ( )

slot

Clear internal channel memory.

Definition at line 297 of file QDaqChannel.cpp.

void QDaqChannel::detach ( )

virtual

Detach this QDaqObject from the QDaq tree.

This function is called just before the object becomes detached from the QDaq tree.

In the base class implementation it first calls detach() for each child QDaqObject and then signal root that the object is removed from the qdaq tree.

Subclasses may reimplement this function to perform needed actions before detaching.

Reimplemented from QDaqJob.

Definition at line 32 of file QDaqChannel.cpp.

void QDaqChannel::push ( double v )

inlineslot

Insert a value into the channel.

Definition at line 214 of file QDaqChannel.h.

bool QDaqChannel::run ( )

protectedvirtual

Perform channel tasks.

The tasks are performed in the following order:

If channel is of a special type, then its function is performed. E.g. if the type is Random a random number is generated.
averaging is performed
the mean value goes through muParser
the mean value is scaled and shifted (multiplier*v + offset)
the mean value is checked for under/over range

If new data is available the updateWidgets signal is emitted.

Returns: always return true.

Reimplemented from QDaqJob.

Definition at line 214 of file QDaqChannel.cpp.

double QDaqChannel::std ( ) const

inlineslot

Get the current channel value standard deviation.

Definition at line 220 of file QDaqChannel.h.

double QDaqChannel::value ( ) const

inlineslot

Get the current channel value.

Definition at line 218 of file QDaqChannel.h.

Property Documentation

bool QDaqChannel::dataReady

read

True if valid data exist on the channel.

If dataReady is true, then value() & std() return valid numbers.

Definition at line 83 of file QDaqChannel.h.

uint QDaqChannel::depth

readwrite

Averaging depth.

Number of past data values used in averaging.

Definition at line 75 of file QDaqChannel.h.

int QDaqChannel::digits

readwrite

Number of decimal digits to display.

Used when displaying the channel in fixed or scientific format.

Definition at line 50 of file QDaqChannel.h.

double QDaqChannel::forgettingFactor

readwrite

Forgetting factor value.

Only used when this type of averaging is active.

Definition at line 71 of file QDaqChannel.h.

NumberFormat QDaqChannel::format

readwrite

Option for formatting channel data for textual representation.

Used when displaying the channel.

Definition at line 46 of file QDaqChannel.h.

uint QDaqChannel::memsize

read

Channel memory used.

Number of values stored in internal channel memory.

Definition at line 79 of file QDaqChannel.h.

double QDaqChannel::multiplier

readwrite

Channel multiplier.

Applied imediately when data is inserted in the channel by the transformation y=a*x+b. b is the offset and a is the multiplier.

Definition at line 64 of file QDaqChannel.h.

double QDaqChannel::offset

readwrite

Channel offset.

Applied imediately when data is inserted in the channel by the transformation y=a*x+b. b is the offset and a is the multiplier.

Definition at line 59 of file QDaqChannel.h.

QString QDaqChannel::parserExpression

readwrite

muParser Expression.

If set the expression is executed on the channel data. Note that the data goes first through muParser and then they are scaled with multiplier and offset.

Definition at line 88 of file QDaqChannel.h.

QDaqVector QDaqChannel::range

readwrite

Signal range.

When the signal is outside the range an error is raised.

Definition at line 54 of file QDaqChannel.h.

QString QDaqChannel::signalName

readwrite

User supplied signal name.

Used when displaying the channel. It is different from the object name.

Definition at line 38 of file QDaqChannel.h.

QString QDaqChannel::unit

readwrite

User supplied unit of measurement.

Used when displaying the channel.

Definition at line 42 of file QDaqChannel.h.

The documentation for this class was generated from the following files:

/home/george/Dev/rtlab/qdaq/lib/core/QDaqChannel.h
/home/george/Dev/rtlab/qdaq/lib/core/QDaqChannel.cpp

Public Types

Public Slots

Public Member Functions

Protected Member Functions

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Member Function Documentation

Property Documentation