nidaqmx.task.ai_channel
- class nidaqmx._task_modules.channels.ai_channel.AIChannel(task_handle, virtual_or_physical_name, interpreter)[source]
Bases:
nidaqmx._task_modules.channels.channel.ChannelRepresents 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.
- 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.
- 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_db_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_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.
- property ai_accel_units
Specifies the units to use to return acceleration measurements from the channel.
- property ai_acceld_b_ref
Deprecated since version 0.7.0: Use ai_accel_db_ref instead.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- property ai_charge_units
Specifies the units to use to return charge measurements from the channel.
- 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.
- property ai_current_acrms_units
Specifies the units to use to return current RMS measurements from the channel.
- 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.
- 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.
- 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.
- property ai_dig_fltr_type
Specifies the digital filter type.
- 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.
- 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.
- 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.
- property ai_excit_src
Specifies the source of excitation.
- 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.
- 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.
- 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.
- 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.
- 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.
- property ai_gain
Specifies a gain factor to apply to the channel.
- Type
float
- property ai_impedance
Specifies the input impedance of the channel.
- 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.
- 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.
- property ai_lvdt_units
Specifies the units to use to return linear position measurements from the channel.
- 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.
- 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.
- 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.
- property ai_raw_samp_justification
Indicates the justification of a raw sample from the device.
- 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.
- property ai_resistance_units
Specifies the units to use to return resistance measurements.
- 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.
- 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.
- 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_r0
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_r_0
Deprecated since version 0.7.0: Use ai_rtd_r0 instead.
- property ai_rtd_type
Specifies the type of RTD connected to the channel.
- 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.
- property ai_rvdt_units
Specifies the units to use to return angular position measurements from the channel.
- 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.
- property ai_sensor_power_type
Specifies the type of power supplied to the sensor.
- property ai_sensor_power_voltage
Specifies the voltage level for the sensor’s power supply.
- Type
float
- property ai_sound_pressure_db_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_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.
- property ai_sound_pressured_b_ref
Deprecated since version 0.7.0: Use ai_sound_pressure_db_ref instead.
- 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.
- 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.
- 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.
- property ai_term_cfg
Specifies the terminal configuration for the channel.
- 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.
- 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.
- property ai_thrmcpl_type
Specifies the type of thermocouple connected to the channel. Thermocouple types differ in composition and measurement range.
- 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_r1
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_thrmstr_r_1
Deprecated since version 0.7.0: Use ai_thrmstr_r1 instead.
- property ai_torque_units
Specifies in which unit to return torque measurements from the channel.
- 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_db_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_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
Deprecated since version 0.7.0: Use ai_velocity_iepe_sensor_db_ref instead.
- property ai_velocity_units
Specifies in which unit to return velocity measurements from the channel.
- property ai_voltage_acrms_units
Specifies the units to use to return voltage RMS measurements from the channel.
- property ai_voltage_db_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_voltage_units
Specifies the units to use to return voltage measurements from the channel.
- property ai_voltaged_b_ref
Deprecated since version 0.7.0: Use ai_voltage_db_ref instead.
- property chan_type
Indicates the type of the virtual channel.
- 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 the polynomial equation that NI-DAQmx uses to scale values from the native format of the device to amperes. Can be read at any time during a task.
- Type
List[float]
- property pwr_current_setpoint
Specifies the output current, in amperes. If the load draws current greater than the specified value, the device will operate in Constant Current mode.
- Type
float
- property pwr_idle_output_behavior
Specifies whether to disable the output or maintain the existing value after the task is uncommitted.
- property pwr_output_enable
Specifies whether to enable or disable power module output. Can be set while a task is running. Can be read at any time during a task. When a task is running, the output is enabled immediately. Otherwise, the output is not enabled until the task enters the Committed state.
- Type
bool
- property pwr_output_state
Indicates power channel operating state. Can be read at any time during a task.
- property pwr_remote_sense
Specifies whether to use local or remote sense to sense the output voltage. DAQmx Read (Power) will return remote or local voltage based on the Remote Sense attribute value. Reading this property will return the user-defined value.
- property pwr_voltage_dev_scaling_coeff
Indicates the coefficients of the polynomial equation that NI-DAQmx uses to scale values from the native format of the device to volts. Can be read at any time during a task.
- Type
List[float]
- property pwr_voltage_setpoint
Specifies the constant output voltage, in volts. Can be set while a task is running. Can be read at any time during 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.