nidaqmx.stream_readers

class nidaqmx.stream_readers.AnalogMultiChannelReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads samples from one or more analog input channels in an NI-DAQmx task.

read_many_sample(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more floating-point samples from one or more analog input channels in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of floating-point values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property to True may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_one_sample(data, timeout=10)[source]

Reads a single floating-point sample from one or more analog input channels in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the samples requested.

    Each element in the array corresponds to a sample from each channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.AnalogSingleChannelReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads samples from an analog input channel in an NI-DAQmx task.

read_many_sample(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more floating-point samples from a single analog input channel in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_one_sample(timeout=10)[source]

Reads a single floating-point sample from a single analog input channel in a task.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single floating-point sample from the task.

Return type

float

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.AnalogUnscaledReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads unscaled samples from one or more analog input channels in an NI-DAQmx task.

read_int16(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more unscaled 16-bit integer samples from one or more analog input channels in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of unscaled 16-bit integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_int32(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more unscaled 32-bit integer samples from one or more analog input channels in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of unscaled 32-bit integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_uint16(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more unscaled 16-bit unsigned integer samples from one or more analog input channels in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of unscaled 16-bit unsigned integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_uint32(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more unscaled unsigned 32-bit integer samples from one or more analog input channels in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of unscaled 32-bit unsigned integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.CounterReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads samples from a counter input channel in an NI-DAQmx task.

read_many_sample_double(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more floating-point samples from a single counter input channel in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_pulse_frequency(frequencies, duty_cycles, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more pulse samples in terms of frequency from a single counter input channel in a task.

This read method accepts preallocated NumPy arrays to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in preallocated arrays is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • frequencies (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the frequency portion of the pulse samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • duty_cycles (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the duty cycle portion of the pulse samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_pulse_ticks(high_ticks, low_ticks, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more pulse samples in terms of ticks from a single counter input channel in a task.

This read method accepts preallocated NumPy arrays to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in preallocated arrays is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • high_ticks (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 32-bit unsigned integer values to hold the high ticks portion of the pulse samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • low_ticks (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 32-bit unsigned integer values to hold the low ticks portion of the pulse samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_pulse_time(high_times, low_times, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more pulse samples in terms of time from a single counter input channel in a task.

This read method accepts preallocated NumPy arrays to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in preallocated arrays is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • high_times (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the high time portion of the pulse samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • low_times (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the low time portion of the pulse samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_uint32(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 32-bit unsigned integer samples from a single counter input channel in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 32-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_one_sample_double(timeout=10)[source]

Reads a single floating-point sample from a single counter input channel in a task.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single floating-point sample from the

task.

Return type

float

read_one_sample_pulse_frequency(timeout=10)[source]

Reads a pulse sample in terms of frequency from a single counter input channel in a task.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a pulse sample in terms of frequency from the task.

Return type

nidaqmx.types.CtrFreq

read_one_sample_pulse_ticks(timeout=10)[source]

Reads a pulse sample in terms of ticks from a single counter input channel in a task.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a pulse sample in terms of ticks from the task.

Return type

nidaqmx.types.CtrTick

read_one_sample_pulse_time(timeout=10)[source]

Reads a pulse sample in terms of time from a single counter input channel in a task.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a pulse sample in terms of time from the task.

Return type

nidaqmx.types.CtrTime

read_one_sample_uint32(timeout=10)[source]

Reads a single 32-bit unsigned integer sample from a single counter input channel in a task.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single 32-bit unsigned integer sample from the task.

Return type

int

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.DigitalMultiChannelReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads samples from one or more digital input channels in an NI-DAQmx task.

read_many_sample_port_byte(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 8-bit unsigned integer samples from one or more digital input channel in a task.

Use this method for devices with up to 8 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of 8-bit unsigned integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_port_uint16(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 16-bit unsigned integer samples from one or more digital input channels in a task.

Use this method for devices with up to 16 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of 16-bit unsigned integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_port_uint32(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 32-bit unsigned integer samples from one or more digital input channels in a task.

Use this method for devices with up to 32 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of 32-bit unsigned integer values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a sample from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_one_sample_multi_line(data, timeout=10)[source]

Reads a single boolean sample from one or more digital input channels in a task. The channels can contain multiple digital lines.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 2D NumPy array of boolean values to hold the samples requested. The size of the array must be large enough to hold all requested samples from all channels in the task; otherwise, an error is thrown.

    Each row corresponds to a channel in the task. Each column corresponds to a line from each channel. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify with the “channels_to_read” property.

    If the size of the array is too large or the array is shaped incorrectly, the previous statement may not hold true as the samples read may not be separated into rows and columns properly. Set the “verify_array_shape” property on this channel reader object to True to validate that the NumPy array object is shaped properly. Setting this property may marginally adversely impact the performance of the method.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

read_one_sample_one_line(data, timeout=10)[source]

Reads a single boolean sample from one or more digital input channels in a task. The channel can contain only one digital line.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of boolean values to hold the samples requested.

    Each element in the array corresponds to a sample from each channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

read_one_sample_port_byte(data, timeout=10)[source]

Reads a single 8-bit unsigned integer sample from one or more digital input channels in a task.

Use this method for devices with up to 8 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 8-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from each channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

read_one_sample_port_uint16(data, timeout=10)[source]

Reads a single 16-bit unsigned integer sample from one or more digital input channels in a task.

Use this method for devices with up to 16 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 16-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from each channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

read_one_sample_port_uint32(data, timeout=10)[source]

Reads a single 32-bit unsigned integer sample from one or more digital input channels in a task.

Use this method for devices with up to 32 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 32-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from each channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.DigitalSingleChannelReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads samples from a digital input channel in an NI-DAQmx task.

read_many_sample_port_byte(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 8-bit unsigned integer samples from a single digital input channel in a task.

Use this method for devices with up to 8 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 8-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_port_uint16(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 16-bit unsigned integer samples from a single digital input channel in a task.

Use this method for devices with up to 16 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 16-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_many_sample_port_uint32(data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more 32-bit unsigned integer samples from a single digital input channel in a task.

Use this method for devices with up to 32 lines per port.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of 32-bit unsigned integer values to hold the samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

read_one_sample_multi_line(data, timeout=10)[source]

Reads a single boolean sample from a single digital input channel in a task. The channel can contain multiple digital lines.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of boolean values to hold the samples requested.

    Each element in the array corresponds to a sample from a line in the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

read_one_sample_one_line(timeout=10)[source]

Reads a single boolean sample from a single digital input channel in a task. The channel can contain only one digital line.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single boolean sample from the task.

Return type

bool

read_one_sample_port_byte(timeout=10)[source]

Reads a single 8-bit unsigned integer sample from a single digital input channel in a task.

Use this method for devices with up to 8 lines per port.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single 8-bit unsigned integer sample from the task.

Return type

int

read_one_sample_port_uint16(timeout=10)[source]

Reads a single 16-bit unsigned integer sample from a single digital input channel in a task.

Use this method for devices with up to 16 lines per port.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single 16-bit unsigned integer sample from the task.

Return type

int

read_one_sample_port_uint32(timeout=10)[source]

Reads a single 32-bit unsigned integer sample from a single digital input channel in a task.

Use this method for devices with up to 32 lines per port.

Parameters

timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates a single 32-bit unsigned integer sample from the task.

Return type

int

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.PowerSingleChannelBinaryReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads binary samples from an analog input power channel in an NI-DAQmx task.

read_many_sample(voltage_data, current_data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more binary int16 samples from a single analog input power channel in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • voltage_data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of i16 values to hold the voltage samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • current_data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of i16 values to hold the current samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool

class nidaqmx.stream_readers.PowerSingleChannelReader(task_in_stream)[source]

Bases: nidaqmx.stream_readers.ChannelReaderBase

Reads samples from an analog input power channel in an NI-DAQmx task.

read_many_sample(voltage_data, current_data, number_of_samples_per_channel=- 1, timeout=10.0)[source]

Reads one or more floating-point samples from a single analog input power channel in a task.

This read method accepts a preallocated NumPy array to hold the samples requested, which can be advantageous for performance and interoperability with NumPy and SciPy.

Passing in a preallocated array is valuable in continuous acquisition scenarios, where the same array can be used repeatedly in each call to the method.

Parameters
  • voltage_data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the voltage samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • current_data (numpy.ndarray) –

    Specifies a preallocated 1D NumPy array of floating-point values to hold the current samples requested.

    Each element in the array corresponds to a sample from the channel. The size of the array must be large enough to hold all requested samples from the channel in the task; otherwise, an error is thrown.

  • number_of_samples_per_channel (Optional[int]) –

    Specifies the number of samples to read.

    If you set this input to nidaqmx.constants. READ_ALL_AVAILABLE, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

    If the task acquires samples continuously and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, this method reads all the samples currently available in the buffer.

    If the task acquires a finite number of samples and you set this input to nidaqmx.constants.READ_ALL_AVAILABLE, the method waits for the task to acquire all requested samples, then reads those samples. If you set the “read_all_avail_samp” property to True, the method reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

  • timeout (Optional[float]) – Specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the method returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to nidaqmx.constants.WAIT_INFINITELY, the method waits indefinitely. If you set timeout to 0, the method tries once to read the requested samples and returns an error if it is unable to.

Returns

Indicates the number of samples acquired by each channel. NI-DAQmx returns a single value because this value is the same for all channels.

Return type

int

property verify_array_shape

Indicates whether the size and shape of the user-defined NumPy arrays passed to read methods are verified. Defaults to True when this object is instantiated.

Setting this property to True may marginally adversely impact the performance of read methods.

Type

bool