class AnalogOutput(object):
## This function is a constructor for the AnalogOutput class.
#
# It creates the internal variables required to perform functions within the
# class. This function does not initialize any hardware.
def __init__(self):
## The DAQmx task reference.
self.taskRef = Task()
## This is a boolean that is true when the DAQmx task has been initialized.
self.initialized = False
## This is the status of the DAQmx task.
#
# A value greater than 0 means that an error has occurred. When the status
# is greater than 0 an error should be reported by the class.
self.status = int32()
## @var sampleRate
# This is the sample rate of the analog output.
self._sampleRate = 100e3
## @var numChannels
# This is the number of channels configured in the task.
self._numChannels = 0
## @var samplesPerChannel
# This is the number of samples per channel that will be
# generated in Finite mode.
self._samplesPerChannel = 100
## @var clkSource
# This is the sample clock source terminal. It can be set to an
# internal clock or external clock such as a PFI line i.e. "/PXI1Slot3/PFI15."
self._clkSource = ''
## @var startTriggerSource
# This is the start trigger source terminal. The software
# ignores this value when the triggerType is set to "Software". Otherwise when
# the triggerType is "Hardware," this terminal is used to start analog
# generation. Example Value: "/PXI1Slot3/PFI0"
self._startTriggerSource = ''
## @var pauseTriggerSource
# The source terminal of the pause trigger. This can be
# any PFI or backplane trigger such as 'PFI5' and 'PXI_TRIG5'
self._pauseTriggerSource = ''
## This is the start trigger terminal of the NI-Sync card.
#
# Setting this value will make sure that the start trigger will be
# propogated through the PXI backplane. If there is no sync card needed
# leave the value default.
self.startTriggerSyncCard = ''
## This is the mode of operation for the analog outputs.
#
# There are currently three modes available. Static mode is where one
# static voltage is set with no need for a sample clock. Finite mode is
# where a finite number of voltages will be set at a sample clock rate.
# Continuous mode is where a sequence of voltages are generated at a sample
# rate and then repeated until the stop() method is called.
self.mode = dutil.Mode.Finite
## The trigger type for the analog outputs.
#
# There are currently two trigger types - "Software" and
# "Hardware." The "Software" mode means that analog output channels are not
# syncronized. While "Hardware" means that analog output channels are
# syncronized to a start trigger. The startTriggerSouce attribute must be
# configured appropriately.
self.triggerType = dutil.TriggerType.Software
## The number of times to iterate over a Finite number of samples.
#
# This value is only useful in the "Finite" mode. It is the number of
# times that a sequence of voltages will be looped. The default is allways 1.
self.loops = 1
## The estimated time to generate the samples for a Finite generation.
#
# Once the input buffer of the analog input is configured, the
# amount of time it takes to generate the voltages in the buffer can be
# estimated. This is a function of the sample rate and the number of samples
# per channel. (This attribute is for internal use only. This attribute may
# not return an accurate value.)
self.estAcqTime = 0
## The analog output buffer.
#
# This is the data that is stored in the buffer of the Analog Output card.
self.buff = None
self._timeoutPad = 0.01
def _getDone(self):
done = bool32()
if self.initialized:
self.status = self.taskRef.GetTaskComplete(ctypes.byref(done))
else:
done.value = 1
return bool(done.value)
## @var done
# Returns the task done status.
#
# This mode works differently depending on the mode. <br />
# <ul>
# <li><B>Static and Continuous</B>: done is false after a start
# method and true</li>
# only after a stop method.
# <li><B>Finite</B>: done is false until all samples are
# generated.</li></ul>
done = property(_getDone)
def _getPauseTriggerSource(self):
if self.initialized:
buffSize = uInt32(255)
buff = ctypes.create_string_buffer(buffSize.value)
self.status = self.taskRef.GetDigLvlPauseTrigSrc(buff, buffSize)
self._pauseTriggerSource = buff.value
return self._pauseTriggerSource
def _setPauseTriggerSource(self, value):
if self.initialized:
if value == '':
self.status = self.taskRef.SetPauseTrigType(DAQmx_Val_None)
self.status = self.taskRef.ResetDigLvlPauseTrigSrc()
else:
self.status = self.taskRef.SetDigLvlPauseTrigWhen(
DAQmx_Val_High)
self.status = self.taskRef.SetPauseTrigType(DAQmx_Val_DigLvl)
self.status = self.taskRef.SetDigLvlPauseTrigSrc(value)
self._pauseTriggerSource = value
pauseTriggerSource = property(_getPauseTriggerSource,
_setPauseTriggerSource)
## Initializes the analog outputs based on the object's configuration.
# @param self The object pointer.
# @param physicalChannel A string representing the device and analog
# output channels. Example Value: "PXI1Slot3/ao0:7"
def init(self, physicalChannel):
self.__createTask(physicalChannel)
self.initialized = True
#Finite Mode
if self.mode == dutil.Mode.Finite:
self.status = self.taskRef.SetWriteRegenMode(DAQmx_Val_AllowRegen)
self.__configTiming(DAQmx_Val_FiniteSamps)
#Continuous Mode
elif self.mode == dutil.Mode.Continuous:
self.status = self.taskRef.SetWriteRegenMode(DAQmx_Val_AllowRegen)
self.__configTiming(DAQmx_Val_ContSamps)
#Static Mode
elif self.mode == dutil.Mode.Static:
self.setSampleRate(self._sampleRate)
self.setSamplesPerChannel(1)
self.pauseTriggerSource = self._pauseTriggerSource
#print self.samplesPerChannel
#print self._sampleRate
#print self.clkSource
#print self.startTriggerSource
## This function returns the samples per channel configured in the DAQmx Task.
# @param self The object pointer.
def getSamplesPerChannel(self):
if self.initialized:
samplesPerChannel = uInt64()
self.status = self.taskRef.GetSampQuantSampPerChan(
ctypes.byref(samplesPerChannel))
self._samplesPerChannel = samplesPerChannel.value
return self._samplesPerChannel
## This function sets the samples per channel in the DAQmx Task.
# @param self The object pointer.
# @param value The value to set the samples per channel.
def setSamplesPerChannel(self, value):
if self.initialized:
self.status = self.taskRef.SetSampQuantSampPerChan(uInt64(value))
self._samplesPerChannel = value
## This funciton deletes the samplesPerChannel variable inside the AnalogOutput
# object.
#
# It is an internal function that is called in the class destructor. It should
# not be called.
def _delSamplesPerChannel(self):
"""
This funciton deletes the samplesPerChannel variable inside the AnalogOutput
object. It is an internal function that is called in the class destructor.
It should not be called.
"""
del self._samplesPerChannel
samplesPerChannel = property(getSamplesPerChannel, setSamplesPerChannel,
_delSamplesPerChannel)
## This function returns the sample clock source configured in the DAQmx Task.
# @param self The object pointer.
def getClkSource(self):
if self.initialized:
buffSize = uInt32(255)
buff = ctypes.create_string_buffer(buffSize.value)
self.status = self.taskRef.GetSampClkSrc(buff, buffSize)
self._clkSource = buff.value
return self._clkSource
## This function sets the sample clock source in the DAQmx Task.
# @param self The object pointer.
# @param value The string value for the clock source terminal.
def setClkSource(self, value):
if self.initialized:
self.status = self.taskRef.SetSampClkSrc(value)
value = self.getClkSource()
self._clkSource = value
## This function deletes the clkSource variable within the AnalogOutput object.
#
# It is an internal function that is called in the class destructor. It should
# not be called.
def _delClkSource(self):
del self._clkSource
clkSource = property(getClkSource, setClkSource, _delClkSource)
## This function return the start trigger source configured in the DAQmx Task.
# @param self The object pointer.
def getStartTriggerSource(self):
if self.initialized:
buffSize = uInt32(255)
buff = ctypes.create_string_buffer(buffSize.value)
self.status = self.taskRef.GetDigEdgeStartTrigSrc(buff, buffSize)
self._startTriggerSource = buff.value
return self._startTriggerSource
## This function sets the start trigger source in the DAQmx Task.
# @param self The object pointer.
# @param value The string vaue of the start trigger source.
# Example value: "\PXI1Slot3\PFI0"
def setStartTriggerSource(self, value):
if self.initialized:
self.status = self.taskRef.SetDigEdgeStartTrigSrc(value)
value = self.getStartTriggerSource()
self._startTriggerSource = value
## This function deletes the startTriggerSource variable within the AnalogOutput object.
#
# It is an internal function that is called in the class destructor. It should
# not be called.
def _delStartTriggerSource(self):
del self._startTriggerSource
startTriggerSource = property(getStartTriggerSource, setStartTriggerSource,
_delStartTriggerSource)
## This function returns the number of channels configured in the DAQmx Task.
# @param self The object pointer.
def getNumChannels(self):
if self.initialized:
numChannels = uInt32()
self.status = self.taskRef.GetTaskNumChans(
ctypes.byref(numChannels))
self._numChannels = numChannels.value
return self._numChannels
numChannels = property(getNumChannels)
## This function returns the sample rate configured in the DAQmx Task.
# @param self The object pointer.
def getSampleRate(self):
if self.initialized:
sampleRate = float64()
self.status = self.taskRef.GetSampClkRate(ctypes.byref(sampleRate))
self._sampleRate = sampleRate.value
return self._sampleRate
## This funciton sets the sample rate in the DAQmx Task.
# @param self The object pointer.
# @param value The value of the sample rate.
def setSampleRate(self, value):
if self.initialized:
self.status = self.taskRef.SetSampClkRate(float64(value))
self._sampleRate = value
## This function deletes the sample rate variable inside the AnalogOutput object.
# @param self The object pointer.
def _delSampleRate(self):
del self._sampleRate
sampleRate = property(getSampleRate, setSampleRate, _delSampleRate)
## This function returns a 1D numpy array of samples with random voltages.
# The returned value is intended to be used to write samples to the buffer with
# the writeToBuffer() method.
# @param self The object pointer.
# @param numChannels The number of channels to generate. If this parameter is
# not provided, Then the function will generate the number of channels configured
# in the analog output task.
def createTestBuffer(self, numChannels=0):
numChannels = numChannels if numChannels > 0 else self.getNumChannels()
return numpy.float64(
numpy.random.rand(self._samplesPerChannel * numChannels))
## This function returns a 1D numpy array of sine waves. The returned
# value is intended to be used to write samples to the buffer with the
# writeToBuffer() method.
# @param self The object pointer.
def createSineTestBuffer(self):
from .createSineWave import createSineWave
numChannels = self.getNumChannels()
for i in range(numChannels):
data = createSineWave(10, 100e3, self._sampleRate,
self._samplesPerChannel,
((2 * numpy.pi) / numChannels) * i)
if i == 0:
sineData = data['amplitude']
else:
sineData = numpy.append(sineData, data['amplitude'])
return sineData
## This function writes the specified values into the buffer.
# @param self The object pointer.
# @param data This is a 1D 64-bit floating point numpy array that contians data
# for each channel. Channels are non-interleaved (channel1 n-samples then
# channel2 n-samples).
def writeToBuffer(self, data):
autostart = self.mode == dutil.Mode.Static
self.buff = data
samplesWritten = int32()
self.status = self.taskRef.WriteAnalogF64(self._samplesPerChannel,
autostart, 10,
DAQmx_Val_GroupByChannel,
data,
ctypes.byref(samplesWritten),
None)
return samplesWritten.value
## This function starts the analog output generation.
# @param self The object pointer.
def start(self):
self.status = self.taskRef.StartTask()
## This functions waits for the analog output generation to complete.
# @param self The object pointer.
def waitUntilDone(self):
sampPerChan = uInt64()
self.status = self.taskRef.GetSampQuantSampPerChan(
ctypes.byref(sampPerChan))
self.estAcqTime = (self.loops * sampPerChan.value) / self._sampleRate
#print 'SamplesPerChannel: ' + str(sampPerChan.value)
#print 'Estimated Acquisition Time: ' + str(self.estAcqTime)
#if (self.estAcqTime >= 0.01 and self.mode != dutil.Mode.Static):
if self.mode != dutil.Mode.Static:
self.status = self.taskRef.WaitUntilTaskDone(
float64(self.estAcqTime + self._timeoutPad))
## This function stops the analog output generation.
# @param self The object pointer.
def stop(self):
self.status = self.taskRef.StopTask()
def __createTask(self, physicalChannel):
"""
This is a private method that creates the Task object for use inside the
AnalogOutput class."""
self.status = self.taskRef.CreateAOVoltageChan(physicalChannel, "",
-10, 10,
DAQmx_Val_Volts, None)
def __configTiming(self, sampleMode):
"""
This is a private method that configures the timing for the Analog Output
class.
"""
totalSamples = self._samplesPerChannel * self.loops
onDemand = bool32()
self.status = self.taskRef.GetOnDemandSimultaneousAOEnable(
ctypes.byref(onDemand))
#print 'On Demand: ' + str(onDemand.value)
#print 'Trigger Type: ' + str(self.triggerType)
#print 'Software Trigger Type: ' + str(dutil.TriggerType.Software)
if self.triggerType == dutil.TriggerType.Software:
#print 'Software Timing'
self.status = self.taskRef.CfgSampClkTiming(
'OnboardClock', float64(self._sampleRate), DAQmx_Val_Rising,
sampleMode, uInt64(totalSamples))
elif self.triggerType == dutil.TriggerType.Hardware:
#print 'Hardware Timing'
self.status = self.taskRef.CfgSampClkTiming(
self._clkSource, float64(self._sampleRate), DAQmx_Val_Falling,
sampleMode, uInt64(totalSamples))
self.status = self.taskRef.CfgDigEdgeStartTrig(
self._startTriggerSource, DAQmx_Val_Rising)
if self.startTriggerSyncCard != '':
DAQmxConnectTerms(self.startTriggerSyncCard,
self._startTriggerSource,
DAQmx_Val_DoNotInvertPolarity)
## This function will close connection to the analog output device and channels.
# @param self The object pointer.
def close(self):
self.initialized = False
if self.startTriggerSyncCard != '':
DAQmxDisconnectTerms(self._startTriggerSource,
self.startTriggerSyncCard)
self.status = self.taskRef.ClearTask()
self.taskRef = Task()
## This is the destructor for the AnalogOutput Class.
# @param self The object pointer.
def __del__(self):
if self.initialized:
self.close()
del self.taskRef
del self.initialized
del self.status
del self.sampleRate
del self._numChannels
del self.samplesPerChannel
del self.clkSource
del self.startTriggerSource
del self.startTriggerSyncCard
del self.mode
del self.triggerType
del self.loops
del self.estAcqTime
