nidaqmx.task.ai_channel

class nidaqmx._task_modules.channels.ai_channel.AIChannel(task_handle, virtual_or_physical_name)[source]

Bases: nidaqmx._task_modules.channels.channel.Channel

Represents one or more analog input virtual channels and their properties.

property ai_ac_excit_freq

Specifies the AC excitation frequency in Hertz.

Type

float

property ai_ac_excit_sync_enable

Specifies whether to synchronize the AC excitation source of the channel to that of another channel. Synchronize the excitation sources of multiple channels to use multichannel sensors. Set this property to False for the master channel and to True for the slave channels.

Type

bool

property ai_ac_excit_wire_mode

Specifies the number of leads on the LVDT or RVDT. Some sensors require you to tie leads together to create a four- or five- wire sensor. Refer to the sensor documentation for more information.

Type

nidaqmx.constants.ACExcitWireMode

property ai_accel_4_wire_dc_voltage_sensitivity

Specifies the sensitivity of the 4 wire DC voltage acceleration sensor connected to the channel. This value is the units you specify with AI.Accel.4WireDCVoltage.SensitivityUnits. Refer to the sensor documentation to determine this value.

Type

float

property ai_accel_4_wire_dc_voltage_sensitivity_units

Specifies the units of AI.Accel.4WireDCVoltage.Sensitivity.

Type

nidaqmx.constants.AccelSensitivityUnits

property ai_accel_charge_sensitivity

Specifies the sensitivity of the charge acceleration sensor connected to the channel. This value is the units you specify with AI.Accel.Charge.SensitivityUnits. Refer to the sensor documentation to determine this value.

Type

float

property ai_accel_charge_sensitivity_units

nidaqmx.constants.AccelChargeSensitivityUnits: Specifies the units of AI.Accel.Charge.Sensitivity.

property ai_accel_sensitivity

Specifies the sensitivity of the accelerometer. This value is in the units you specify with ai_accel_sensitivity_units. Refer to the sensor documentation to determine this value.

Type

float

property ai_accel_sensitivity_units

Specifies the units of ai_accel_sensitivity.

Type

nidaqmx.constants.AccelSensitivityUnits

property ai_accel_units

Specifies the units to use to return acceleration measurements from the channel.

Type

nidaqmx.constants.AccelUnits

property ai_acceld_b_ref

Specifies the decibel reference level in the units of the channel. When you read samples as a waveform, the decibel reference level is included in the waveform attributes.

Type

float

property ai_adc_custom_timing_mode

Specifies the timing mode of the ADC when ai_adc_timing_mode is ADCTimingMode.CUSTOM.

Type

int

property ai_adc_timing_mode

Specifies the ADC timing mode, controlling the tradeoff between speed and effective resolution. Some ADC timing modes provide increased powerline noise rejection. On devices that have an AI Convert clock, this setting affects both the maximum and default values for ai_conv_rate. You must use the same ADC timing mode for all channels on a device, but you can use different ADC timing modes for different devices in the same task.

Type

nidaqmx.constants.ADCTimingMode

property ai_atten

Specifies the amount of attenuation to use.

Type

float

property ai_auto_zero_mode

Specifies how often to measure ground. NI-DAQmx subtracts the measured ground voltage from every sample.

Type

nidaqmx.constants.AutoZeroType

property ai_averaging_win_size

Specifies the number of samples to average while acquiring data. Increasing the number of samples to average reduces noise in your measurement.

Type

int

property ai_bridge_balance_coarse_pot

Specifies by how much to compensate for offset in the signal. This value can be between 0 and 127.

Type

int

property ai_bridge_balance_fine_pot

Specifies by how much to compensate for offset in the signal. This value can be between 0 and 4095.

Type

int

property ai_bridge_cfg

Specifies the type of Wheatstone bridge connected to the channel.

Type

nidaqmx.constants.BridgeConfiguration

property ai_bridge_electrical_units

Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.

Type

nidaqmx.constants.BridgeElectricalUnits

property ai_bridge_initial_ratio

Specifies in volts per volt the ratio of output voltage from the bridge to excitation voltage supplied to the bridge while not under load. NI-DAQmx subtracts this value from any measurements before applying scaling equations. If you set ai_bridge_initial_voltage, NI-DAQmx coerces this property to ai_bridge_initial_voltage divided by ai_excit_actual_val. If you set this property, NI-DAQmx coerces ai_bridge_initial_voltage to the value of this property times ai_excit_actual_val. If you set both this property and ai_bridge_initial_voltage, and their values conflict, NI-DAQmx returns an error. To avoid this error, reset one property to its default value before setting the other.

Type

float

property ai_bridge_initial_voltage

Specifies in volts the output voltage of the bridge while not under load. NI-DAQmx subtracts this value from any measurements before applying scaling equations. If you set ai_bridge_initial_ratio, NI-DAQmx coerces this property to ai_bridge_initial_ratio times ai_excit_actual_val. This property is set by DAQmx Perform Bridge Offset Nulling Calibration. If you set this property, NI-DAQmx coerces ai_bridge_initial_ratio to the value of this property divided by ai_excit_actual_val. If you set both this property and ai_bridge_initial_ratio, and their values conflict, NI- DAQmx returns an error. To avoid this error, reset one property to its default value before setting the other.

Type

float

property ai_bridge_nom_resistance

Specifies in ohms the resistance of the bridge while not under load.

Type

float

property ai_bridge_physical_units

Specifies to which physical unit to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.

Type

nidaqmx.constants.BridgePhysicalUnits

property ai_bridge_poly_forward_coeff

Specifies an list of coefficients for the polynomial that converts electrical values to physical values. Each element of the list corresponds to a term of the equation. For example, if index three of the list is 9, the fourth term of the equation is 9x^3.

Type

List[float]

property ai_bridge_poly_reverse_coeff

Specifies an list of coefficients for the polynomial that converts physical values to electrical values. Each element of the list corresponds to a term of the equation. For example, if index three of the list is 9, the fourth term of the equation is 9x^3.

Type

List[float]

property ai_bridge_scale_type

Specifies the scaling type to use when scaling electrical values from the sensor to physical units.

Type

nidaqmx.constants.ScaleType

property ai_bridge_shunt_cal_enable

Specifies whether to enable a shunt calibration switch. Use ai_bridge_shunt_cal_select to select the switch(es) to enable.

Type

bool

property ai_bridge_shunt_cal_gain_adjust

Specifies the result of a shunt calibration. This property is set by DAQmx Perform Shunt Calibration. NI-DAQmx multiplies data read from the channel by the value of this property. This value should be close to 1.0.

Type

float

property ai_bridge_shunt_cal_select

Specifies which shunt calibration switch(es) to enable. Use ai_bridge_shunt_cal_enable to enable the switch(es) you specify with this property.

Type

nidaqmx.constants.ShuntCalSelect

property ai_bridge_shunt_cal_shunt_cal_a_actual_resistance

Specifies in ohms the actual value of the internal shunt calibration A resistor.

Type

float

property ai_bridge_shunt_cal_shunt_cal_a_resistance

Specifies in ohms the desired value of the internal shunt calibration A resistor.

Type

float

property ai_bridge_shunt_cal_shunt_cal_a_src

Specifies whether to use internal or external shunt when Shunt Cal A is selected.

Type

nidaqmx.constants.BridgeShuntCalSource

property ai_bridge_shunt_cal_shunt_cal_b_actual_resistance

Specifies in ohms the actual value of the internal shunt calibration B resistor.

Type

float

property ai_bridge_shunt_cal_shunt_cal_b_resistance

Specifies in ohms the desired value of the internal shunt calibration B resistor.

Type

float

property ai_bridge_table_electrical_vals

Specifies the list of electrical values that map to the values in ai_bridge_table_physical_vals. Specify this value in the unit indicated by ai_bridge_electrical_units.

Type

List[float]

property ai_bridge_table_physical_vals

Specifies the list of physical values that map to the values in ai_bridge_table_electrical_vals. Specify this value in the unit indicated by ai_bridge_physical_units.

Type

List[float]

property ai_bridge_two_point_lin_first_electrical_val

Specifies the first electrical value, corresponding to ai_bridge_two_point_lin_first_physical_val. Specify this value in the unit indicated by ai_bridge_electrical_units.

Type

float

property ai_bridge_two_point_lin_first_physical_val

Specifies the first physical value, corresponding to ai_bridge_two_point_lin_first_electrical_val. Specify this value in the unit indicated by ai_bridge_physical_units.

Type

float

property ai_bridge_two_point_lin_second_electrical_val

Specifies the second electrical value, corresponding to ai_bridge_two_point_lin_second_physical_val. Specify this value in the unit indicated by ai_bridge_electrical_units.

Type

float

property ai_bridge_two_point_lin_second_physical_val

Specifies the second physical value, corresponding to ai_bridge_two_point_lin_second_electrical_val. Specify this value in the unit indicated by ai_bridge_physical_units.

Type

float

property ai_bridge_units

Specifies in which unit to return voltage ratios from the channel.

Type

nidaqmx.constants.BridgeUnits

property ai_charge_units

Specifies the units to use to return charge measurements from the channel.

Type

nidaqmx.constants.ChargeUnits

property ai_chop_enable

Specifies whether the device will chop its inputs. Chopping removes offset voltages and other low frequency errors.

Type

bool

property ai_coupling

Specifies the coupling for the channel.

Type

nidaqmx.constants.Coupling

property ai_current_acrms_units

Specifies the units to use to return current RMS measurements from the channel.

Type

nidaqmx.constants.CurrentUnits

property ai_current_shunt_loc

nidaqmx.constants.CurrentShuntResistorLocation: Specifies the shunt resistor location for current measurements.

property ai_current_shunt_resistance

Specifies in ohms the external shunt resistance for current measurements.

Type

float

property ai_current_units

Specifies the units to use to return current measurements from the channel.

Type

nidaqmx.constants.CurrentUnits

property ai_custom_scale

Specifies the name of a custom scale for the channel.

Type

nidaqmx.system.scale.Scale

property ai_data_xfer_custom_threshold

Specifies the number of samples that must be in the FIFO to transfer data from the device if ai_data_xfer_req_cond is InputDataTransferCondition.ONBOARD_MEMORY_CUSTOM_THRESHOLD.

Type

int

property ai_data_xfer_max_rate

Specifies the rate in B/s to transfer data from the device. If this value is not set, then the device will transfer data at a rate based on the bus detected. Modify this value to affect performance under different combinations of operating system, configuration, and device.

Type

float

property ai_data_xfer_mech

nidaqmx.constants.DataTransferActiveTransferMode: Specifies the data transfer mode for the device.

property ai_data_xfer_req_cond

Specifies under what condition to transfer data from the onboard memory of the device to the buffer.

Type

nidaqmx.constants.InputDataTransferCondition

property ai_dc_offset

Specifies the DC value to add to the input range of the device. Use ai_rng_high and ai_rng_low to specify the input range. This offset is in the native units of the device .

Type

float

property ai_dev_scaling_coeff

Indicates the coefficients of a polynomial equation that NI-DAQmx uses to scale values from the native format of the device to volts. Each element of the list corresponds to a term of the equation. For example, if index two of the list is 4, the third term of the equation is 4x^2. Scaling coefficients do not account for any custom scales or sensors contained by the channel.

Type

List[float]

property ai_dig_fltr_bandpass_center_freq

Specifies the center frequency of the passband for the digital filter.

Type

float

property ai_dig_fltr_bandpass_width

Specifies the width of the passband centered around the center frequency for the digital filter.

Type

float

property ai_dig_fltr_coeff

Specifies the digital filter coefficients.

Type

List[float]

property ai_dig_fltr_enable

Specifies whether the digital filter is enabled or disabled.

Type

bool

property ai_dig_fltr_highpass_cutoff_freq

Specifies the highpass cutoff frequency of the digital filter.

Type

float

property ai_dig_fltr_lowpass_cutoff_freq

Specifies the lowpass cutoff frequency of the digital filter.

Type

float

property ai_dig_fltr_notch_center_freq

Specifies the center frequency of the stopband for the digital filter.

Type

float

property ai_dig_fltr_notch_width

Specifies the width of the stopband centered around the center frequency for the digital filter.

Type

float

property ai_dig_fltr_order

Specifies the order of the digital filter.

Type

int

property ai_dig_fltr_response

Specifies the digital filter response.

Type

nidaqmx.constants.FilterResponse

property ai_dig_fltr_type

Specifies the digital filter type.

Type

nidaqmx.constants.FilterType

property ai_dither_enable

Specifies whether to enable dithering. Dithering adds Gaussian noise to the input signal. You can use dithering to achieve higher resolution measurements by over sampling the input signal and averaging the results.

Type

bool

property ai_eddy_current_prox_sensitivity

Specifies the sensitivity of the eddy current proximity probe . This value is in the units you specify with ai_eddy_current_prox_sensitivity_units. Refer to the sensor documentation to determine this value.

Type

float

property ai_eddy_current_prox_sensitivity_units

nidaqmx.constants.EddyCurrentProxProbeSensitivityUnits: Specifies the units of ai_eddy_current_prox_sensitivity.

property ai_eddy_current_prox_units

Specifies the units to use to return proximity measurements from the channel.

Type

nidaqmx.constants.LengthUnits

property ai_enhanced_alias_rejection_enable

Specifies whether to enable enhanced alias rejection. Leave this property set to the default value for most applications.

Type

bool

property ai_excit_actual_val

Specifies the actual amount of excitation supplied by an internal excitation source. If you read an internal excitation source more precisely with an external device, set this property to the value you read. NI-DAQmx ignores this value for external excitation. When performing shunt calibration, some devices set this property automatically.

Type

float

property ai_excit_d_cor_ac

Specifies if the excitation supply is DC or AC.

Type

nidaqmx.constants.ExcitationDCorAC

property ai_excit_idle_output_behavior

nidaqmx.constants.ExcitationIdleOutputBehavior: Specifies whether this channel will disable excitation after the task is uncommitted. Setting this to Zero Volts or Amps disables excitation after task uncommit. Setting this attribute to Maintain Existing Value leaves the excitation on after task uncommit.

property ai_excit_sense

Specifies whether to use local or remote sense to sense excitation.

Type

nidaqmx.constants.Sense

property ai_excit_src

Specifies the source of excitation.

Type

nidaqmx.constants.ExcitationSource

property ai_excit_use_for_scaling

Specifies if NI-DAQmx divides the measurement by the excitation. You should typically set this property to True for ratiometric transducers. If you set this property to True, set ai_max and ai_min to reflect the scaling.

Type

bool

property ai_excit_use_multiplexed

Specifies if the SCXI-1122 multiplexes the excitation to the upper half of the channels as it advances through the scan list.

Type

bool

property ai_excit_val

Specifies the amount of excitation that the sensor requires. If ai_excit_voltage_or_current is ExcitationVoltageOrCurrent.USE_VOLTAGE, this value is in volts. If ai_excit_voltage_or_current is ExcitationVoltageOrCurrent.USE_CURRENT, this value is in amperes.

Type

float

property ai_excit_voltage_or_current

Specifies if the channel uses current or voltage excitation.

Type

nidaqmx.constants.ExcitationVoltageOrCurrent

property ai_filter_delay

Indicates the amount of time between when the ADC samples data and when the sample is read by the host device. This value is in the units you specify with ai_filter_delay_units. You can adjust this amount of time using ai_filter_delay_adjustment.

Type

float

property ai_filter_delay_adjustment

Specifies the amount of filter delay that gets removed if ai_remove_filter_delay is enabled. This delay adjustment is in addition to the value indicated by ai_filter_delay. This delay adjustment is in the units you specify with ai_filter_delay_units.

Type

float

property ai_filter_delay_units

Specifies the units of ai_filter_delay and ai_filter_delay_adjustment.

Type

nidaqmx.constants.DigitalWidthUnits

property ai_filter_enable

Specifies the corresponding filter enable/disable state.

Type

bool

property ai_filter_freq

Specifies the corresponding filter frequency (cutoff or center) of the filter response.

Type

float

property ai_filter_order

Specifies the corresponding filter order and defines the slope of the filter response.

Type

int

property ai_filter_response

Specifies the corresponding filter response and defines the shape of the filter response.

Type

nidaqmx.constants.FilterResponse

property ai_force_iepe_sensor_sensitivity

Specifies the sensitivity of the IEPE force sensor connected to the channel. Specify this value in the unit indicated by ai_force_iepe_sensor_sensitivity_units.

Type

float

property ai_force_iepe_sensor_sensitivity_units

nidaqmx.constants.ForceIEPESensorSensitivityUnits: Specifies the units for ai_force_iepe_sensor_sensitivity.

property ai_force_read_from_chan

Specifies whether to read from the channel if it is a cold-junction compensation channel. By default, DAQmx Read does not return data from cold-junction compensation channels. Setting this property to True forces read operations to return the cold-junction compensation channel data with the other channels in the task.

Type

bool

property ai_force_units

Specifies in which unit to return force or load measurements from the channel.

Type

nidaqmx.constants.ForceUnits

property ai_freq_hyst

Specifies in volts a window below ai_freq_thresh_voltage. The input voltage must pass below ai_freq_thresh_voltage minus this value before NI- DAQmx recognizes a waveform repetition at ai_freq_thresh_voltage. Hysteresis can improve the measurement accuracy when the signal contains noise or jitter.

Type

float

property ai_freq_thresh_voltage

Specifies the voltage level at which to recognize waveform repetitions. You should select a voltage level that occurs only once within the entire period of a waveform. You also can select a voltage that occurs only once while the voltage rises or falls.

Type

float

property ai_freq_units

Specifies the units to use to return frequency measurements from the channel.

Type

nidaqmx.constants.FrequencyUnits

property ai_gain

Specifies a gain factor to apply to the channel.

Type

float

property ai_impedance

Specifies the input impedance of the channel.

Type

nidaqmx.constants.Impedance1

property ai_input_limits_fault_detect_enable

Specifies whether to enable input limits fault detection.

Type

bool

property ai_input_limits_fault_detect_lower_limit

Specifies the level of the lower limit for input limits detection. An input sample outside the upper and lower bounds causes a fault. Note: Fault detection applies to both positive and negative inputs. For instance, if you specify a lower limit of 2 mA and an upper limit of 12 mA, NI-DAQmx detects a fault at 15 mA and -15 mA, but not at -6 mA because it is in the range of -12 mA to -2 mA.

Type

float

property ai_input_limits_fault_detect_upper_limit

Specifies the level of the upper limit for input limits detection. An input sample outside the upper and lower bounds causes a fault. Note: Fault detection applies to both positive and negative inputs. For instance, if you specify a lower limit of 2 mA and an upper limit of 12 mA, NI-DAQmx detects a fault at 15 mA and -15 mA, but not at -6 mA because it is in the range of -12 mA to -2 mA.

Type

float

property ai_input_src

Specifies the source of the channel. You can use the signal from the I/O connector or one of several calibration signals. Certain devices have a single calibration signal bus. For these devices, you must specify the same calibration signal for all channels you connect to a calibration signal.

Type

str

property ai_lead_wire_resistance

Specifies in ohms the resistance of the wires that lead to the sensor.

Type

float

property ai_lossy_lsb_removal_compressed_samp_size

Specifies the number of bits to return in a raw sample when ai_raw_data_compression_type is set to RawDataCompressionType.LOSSY_LSB_REMOVAL.

Type

int

property ai_lowpass_cutoff_freq

Specifies the frequency in Hertz that corresponds to the -3dB cutoff of the filter.

Type

float

property ai_lowpass_enable

Specifies whether to enable the lowpass filter of the channel.

Type

bool

property ai_lowpass_switch_cap_clk_src

Specifies the source of the filter clock. If you need a higher resolution for the filter, you can supply an external clock to increase the resolution. Refer to the SCXI-1141/1142/1143 User Manual for more information.

Type

nidaqmx.constants.SourceSelection

property ai_lowpass_switch_cap_ext_clk_div

Specifies the divisor for the external clock when you set ai_lowpass_switch_cap_clk_src to SourceSelection.EXTERNAL. On the SCXI-1141, SCXI-1142, and SCXI-1143, NI-DAQmx determines the filter cutoff by using the equation f/(100*n), where f is the external frequency, and n is the external clock divisor. Refer to the SCXI-1141/1142/1143 User Manual for more information.

Type

int

property ai_lowpass_switch_cap_ext_clk_freq

Specifies the frequency of the external clock when you set ai_lowpass_switch_cap_clk_src to SourceSelection.EXTERNAL. NI-DAQmx uses this frequency to set the pre- and post- filters on the SCXI-1141, SCXI-1142, and SCXI-1143. On those devices, NI-DAQmx determines the filter cutoff by using the equation f/(100*n), where f is the external frequency, and n is the external clock divisor. Refer to the SCXI-1141/1142/1143 User Manual for more information.

Type

float

property ai_lowpass_switch_cap_out_clk_div

Specifies the divisor for the output clock. NI-DAQmx uses the cutoff frequency to determine the output clock frequency. Refer to the SCXI-1141/1142/1143 User Manual for more information.

Type

int

property ai_lvdt_sensitivity

Specifies the sensitivity of the LVDT. This value is in the units you specify with ai_lvdt_sensitivity_units. Refer to the sensor documentation to determine this value.

Type

float

property ai_lvdt_sensitivity_units

Specifies the units of ai_lvdt_sensitivity.

Type

nidaqmx.constants.LVDTSensitivityUnits

property ai_lvdt_units

Specifies the units to use to return linear position measurements from the channel.

Type

nidaqmx.constants.LengthUnits

property ai_max

Specifies the maximum value you expect to measure. This value is in the units you specify with a units property. When you query this property, it returns the coerced maximum value that the device can measure with the current settings.

Type

float

property ai_meas_type

Indicates the measurement to take with the analog input channel and in some cases, such as for temperature measurements, the sensor to use.

Type

nidaqmx.constants.UsageTypeAI

property ai_mem_map_enable

Specifies for NI-DAQmx to map hardware registers to the memory space of the application, if possible. Normally, NI- DAQmx maps hardware registers to memory accessible only to the kernel. Mapping the registers to the memory space of the application increases performance. However, if the application accesses the memory space mapped to the registers, it can adversely affect the operation of the device and possibly result in a system crash.

Type

bool

property ai_microphone_sensitivity

Specifies the sensitivity of the microphone. This value is in mV/Pa. Refer to the sensor documentation to determine this value.

Type

float

property ai_min

Specifies the minimum value you expect to measure. This value is in the units you specify with a units property. When you query this property, it returns the coerced minimum value that the device can measure with the current settings.

Type

float

property ai_open_chan_detect_enable

Specifies whether to enable open channel detection.

Type

bool

property ai_open_thrmcpl_detect_enable

Specifies whether to apply the open thermocouple detection bias voltage to the channel. Changing the value of this property on a channel may require settling time before the data returned is valid. To compensate for this settling time, discard unsettled data or add a delay between committing and starting the task. Refer to your device specifications for the required settling time. When open thermocouple detection is enabled, use open_thrmcpl_chans_exist to determine if any channels were open.

Type

bool

property ai_overcurrent_detect_enable

Specifies whether to enable overcurrent detection.

Type

bool

property ai_power_supply_fault_detect_enable

Specifies whether to enable power supply fault detection.

Type

bool

property ai_pressure_units

Specifies in which unit to return pressure measurements from the channel.

Type

nidaqmx.constants.PressureUnits

property ai_probe_atten

Specifies the amount of attenuation provided by the probe connected to the channel. Specify this attenuation as a ratio.

Type

float

property ai_raw_data_compression_type

Specifies the type of compression to apply to raw samples returned from the device.

Type

nidaqmx.constants.RawDataCompressionType

property ai_raw_samp_justification

Indicates the justification of a raw sample from the device.

Type

nidaqmx.constants.DataJustification

property ai_raw_samp_size

Indicates in bits the size of a raw sample from the device.

Type

int

property ai_remove_filter_delay

Specifies if filter delay removal is enabled on the device.

Type

bool

property ai_resistance_cfg

Specifies the resistance configuration for the channel. NI-DAQmx uses this value for any resistance-based measurements, including temperature measurement using a thermistor or RTD.

Type

nidaqmx.constants.ResistanceConfiguration

property ai_resistance_units

Specifies the units to use to return resistance measurements.

Type

nidaqmx.constants.ResistanceUnits

property ai_resolution

Indicates the resolution of the analog-to-digital converter of the channel. This value is in the units you specify with ai_resolution_units.

Type

float

property ai_resolution_units

Indicates the units of ai_resolution.

Type

nidaqmx.constants.ResolutionType

property ai_rng_high

Specifies the upper limit of the input range of the device. This value is in the native units of the device. On E Series devices, for example, the native units is volts.

Type

float

property ai_rng_low

Specifies the lower limit of the input range of the device. This value is in the native units of the device. On E Series devices, for example, the native units is volts.

Type

float

property ai_rosette_strain_gage_gage_orientation

Specifies gage orientation in degrees with respect to the X axis.

Type

float

property ai_rosette_strain_gage_rosette_meas_type

nidaqmx.constants.StrainGageRosetteMeasurementType: Specifies the type of rosette measurement.

property ai_rosette_strain_gage_rosette_type

Indicates the type of rosette gage.

Type

nidaqmx.constants.StrainGageRosetteType

property ai_rosette_strain_gage_strain_chans

Indicates the raw strain channels that comprise the strain rosette.

Type

List[str]

property ai_rtd_a

Specifies the ‘A’ constant of the Callendar-Van Dusen equation. NI-DAQmx requires this value when you use a custom RTD.

Type

float

property ai_rtd_b

Specifies the ‘B’ constant of the Callendar-Van Dusen equation. NI-DAQmx requires this value when you use a custom RTD.

Type

float

property ai_rtd_c

Specifies the ‘C’ constant of the Callendar-Van Dusen equation. NI-DAQmx requires this value when you use a custom RTD.

Type

float

property ai_rtd_r_0

Specifies in ohms the sensor resistance at 0 deg C. The Callendar-Van Dusen equation requires this value. Refer to the sensor documentation to determine this value.

Type

float

property ai_rtd_type

Specifies the type of RTD connected to the channel.

Type

nidaqmx.constants.RTDType

property ai_rvdt_sensitivity

Specifies the sensitivity of the RVDT. This value is in the units you specify with ai_rvdt_sensitivity_units. Refer to the sensor documentation to determine this value.

Type

float

property ai_rvdt_sensitivity_units

Specifies the units of ai_rvdt_sensitivity.

Type

nidaqmx.constants.RVDTSensitivityUnits

property ai_rvdt_units

Specifies the units to use to return angular position measurements from the channel.

Type

nidaqmx.constants.AngleUnits

property ai_samp_and_hold_enable

Specifies whether to enable the sample and hold circuitry of the device. When you disable sample and hold circuitry, a small voltage offset might be introduced into the signal. You can eliminate this offset by using ai_auto_zero_mode to perform an auto zero on the channel.

Type

bool

property ai_sensor_power_cfg

Specifies whether to turn on the sensor’s power supply or to leave the configuration unchanged.

Type

nidaqmx.constants.SensorPowerCfg

property ai_sensor_power_type

Specifies the type of power supplied to the sensor.

Type

nidaqmx.constants.SensorPowerType

property ai_sensor_power_voltage

Specifies the voltage level for the sensor’s power supply.

Type

float

property ai_sound_pressure_max_sound_pressure_lvl

Specifies the maximum instantaneous sound pressure level you expect to measure. This value is in decibels, referenced to 20 micropascals. NI-DAQmx uses the maximum sound pressure level to calculate values in pascals for ai_max and ai_min for the channel.

Type

float

property ai_sound_pressure_units

Specifies the units to use to return sound pressure measurements from the channel.

Type

nidaqmx.constants.SoundPressureUnits

property ai_sound_pressured_b_ref

Specifies the decibel reference level in the units of the channel. When you read samples as a waveform, the decibel reference level is included in the waveform attributes. NI- DAQmx also uses the decibel reference level when converting ai_sound_pressure_max_sound_pressure_lvl to a voltage level.

Type

float

property ai_strain_force_read_from_chan

Specifies whether the data is returned by DAQmx Read when set on a raw strain channel that is part of a rosette configuration.

Type

bool

property ai_strain_gage_cfg

Specifies the bridge configuration of the strain gages.

Type

nidaqmx.constants.StrainGageBridgeType

property ai_strain_gage_gage_factor

Specifies the sensitivity of the strain gage. Gage factor relates the change in electrical resistance to the change in strain. Refer to the sensor documentation for this value.

Type

float

property ai_strain_gage_poisson_ratio

Specifies the ratio of lateral strain to axial strain in the material you are measuring.

Type

float

property ai_strain_units

Specifies the units to use to return strain measurements from the channel.

Type

nidaqmx.constants.StrainUnits

property ai_teds_is_teds

Indicates if the virtual channel was initialized using a TEDS bitstream from the corresponding physical channel.

Type

bool

property ai_teds_units

Indicates the units defined by TEDS information associated with the channel.

Type

str

property ai_temp_units

Specifies the units to use to return temperature measurements from the channel.

Type

nidaqmx.constants.TemperatureUnits

property ai_term_cfg

Specifies the terminal configuration for the channel.

Type

nidaqmx.constants.TerminalConfiguration

property ai_thrmcpl_cjc_chan

nidaqmx._task_modules.channels.channel.Channel: Indicates the channel that acquires the temperature of the cold junction if ai_thrmcpl_cjc_src is CJCSource1.SCANNABLE_CHANNEL. If the channel is a temperature channel, NI-DAQmx acquires the temperature in the correct units. Other channel types, such as a resistance channel with a custom sensor, must use a custom scale to scale values to degrees Celsius.

property ai_thrmcpl_cjc_src

Indicates the source of cold-junction compensation.

Type

nidaqmx.constants.CJCSource

property ai_thrmcpl_cjc_val

Specifies the temperature of the cold junction if ai_thrmcpl_cjc_src is CJCSource1.CONSTANT_USER_VALUE. Specify this value in the units of the measurement.

Type

float

property ai_thrmcpl_lead_offset_voltage

Specifies the lead offset nulling voltage to subtract from measurements on a device. This property is ignored if open thermocouple detection is disabled.

Type

float

property ai_thrmcpl_scale_type

Specifies the method or equation form that the thermocouple scale uses.

Type

nidaqmx.constants.ScaleType

property ai_thrmcpl_type

Specifies the type of thermocouple connected to the channel. Thermocouple types differ in composition and measurement range.

Type

nidaqmx.constants.ThermocoupleType

property ai_thrmstr_a

Specifies the ‘A’ constant of the Steinhart-Hart thermistor equation.

Type

float

property ai_thrmstr_b

Specifies the ‘B’ constant of the Steinhart-Hart thermistor equation.

Type

float

property ai_thrmstr_c

Specifies the ‘C’ constant of the Steinhart-Hart thermistor equation.

Type

float

property ai_thrmstr_r_1

Specifies in ohms the value of the reference resistor for the thermistor if you use voltage excitation. NI-DAQmx ignores this value for current excitation.

Type

float

property ai_torque_units

Specifies in which unit to return torque measurements from the channel.

Type

nidaqmx.constants.TorqueUnits

property ai_usb_xfer_req_count

Specifies the maximum number of simultaneous USB transfers used to stream data. Modify this value to affect performance under different combinations of operating system and device.

Type

int

property ai_usb_xfer_req_size

Specifies the maximum size of a USB transfer request in bytes. Modify this value to affect performance under different combinations of operating system and device.

Type

int

property ai_velocity_iepe_sensor_sensitivity

Specifies the sensitivity of the IEPE velocity sensor connected to the channel. Specify this value in the unit indicated by ai_velocity_iepe_sensor_sensitivity_units.

Type

float

property ai_velocity_iepe_sensor_sensitivity_units

nidaqmx.constants.VelocityIEPESensorSensitivityUnits: Specifies the units for ai_velocity_iepe_sensor_sensitivity.

property ai_velocity_iepe_sensord_b_ref

Specifies the decibel reference level in the units of the channel. When you read samples as a waveform, the decibel reference level is included in the waveform attributes.

Type

float

property ai_velocity_units

Specifies in which unit to return velocity measurements from the channel.

Type

nidaqmx.constants.VelocityUnits

property ai_voltage_acrms_units

Specifies the units to use to return voltage RMS measurements from the channel.

Type

nidaqmx.constants.VoltageUnits

property ai_voltage_units

Specifies the units to use to return voltage measurements from the channel.

Type

nidaqmx.constants.VoltageUnits

property ai_voltaged_b_ref

Specifies the decibel reference level in the units of the channel. When you read samples as a waveform, the decibel reference level is included in the waveform attributes.

Type

float

property chan_type

Indicates the type of the virtual channel.

Type

nidaqmx.constants.ChannelType

property channel_names

Specifies the unflattened list of the virtual channels.

Type

List[str]

property description

Specifies a user-defined description for the channel.

Type

str

property is_global

Indicates whether the channel is a global channel.

Type

bool

property name

Specifies the name of the virtual channel this object represents.

Type

str

property physical_channel

nidaqmx.system.physical_channel.PhysicalChannel: Specifies the name of the physical channel upon which this virtual channel is based.

property pwr_current_dev_scaling_coeff

Indicates the coefficients of a polynomial equation that NI-DAQmx uses to scale values from the native format of the device to amperes. Property is readable anytime in a task.

Type

List[float]

property pwr_current_setpoint

Specifies the output current, in amperes unit. If the load draws current exceeding this specified value, the device will operate under Constant Current mode.

Type

float

property pwr_idle_output_behavior

Specifies whether output will be disabled or maintaining existing value after the task is uncommitted.

Type

nidaqmx.constants.PowerIdleOutputBehavior

property pwr_output_enable

Specifies to enables or disables output of power module. By default, the output is to be enabled but it can also be explicitly enabled or disabled on set. Property is settable even while a task is running and it is readable anytime in a task. When task is not running, enabling the output does not take effect until Daqmx Commit function is called. When task is running, enabling the output will take effect immediately.

Type

bool

property pwr_output_state

Indicates the operating state of the power channel. Property is readable anytime in a task.

Type

nidaqmx.constants.PowerOutputState

property pwr_remote_sense

Specifies whether to use remote sense or local sense of the output voltage. DAQmx Read (Power) will return remote voltage if Remote Sense attribute is set to Remote. DAQmx Read (Power) will return local voltage if Remote Sense attribute is set to Local. Reading this property will return user defined value.

Type

nidaqmx.constants.Sense

property pwr_voltage_dev_scaling_coeff

Indicates the coefficients of a polynomial equation that NI-DAQmx uses to scale values from the native format of the device to volts. Property is readable anytime in a task.

Type

List[float]

property pwr_voltage_setpoint

Specifies the constant output voltage, in volts. Property is settable even while a task is running and it is readable anytime in a task.

Type

float

save(save_as='', author='', overwrite_existing_channel=False, allow_interactive_editing=True, allow_interactive_deletion=True)

Saves this local or global channel to MAX as a global channel.

Parameters
  • save_as (Optional[str]) – Is the name to save the task, global channel, or custom scale as. If you do not specify a value for this input, NI-DAQmx uses the name currently assigned to the task, global channel, or custom scale.

  • author (Optional[str]) – Is a name to store with the task, global channel, or custom scale.

  • overwrite_existing_channel (Optional[bool]) – Specifies whether to overwrite a global channel of the same name if one is already saved in MAX. If this input is False and a global channel of the same name is already saved in MAX, this function returns an error.

  • allow_interactive_editing (Optional[bool]) – Specifies whether to allow the task, global channel, or custom scale to be edited in the DAQ Assistant. If allow_interactive_editing is True, the DAQ Assistant must support all task or global channel settings.

  • allow_interactive_deletion (Optional[bool]) – Specifies whether to allow the task, global channel, or custom scale to be deleted through MAX.

property sync_unlock_behavior

Specifies the action to take if the target loses its synchronization to the grand master.

Type

nidaqmx.constants.SyncUnlockBehavior