nidaqmx.task.channels

class nidaqmx.task.channels.Channel(task_handle, virtual_or_physical_name, interpreter)

Bases: object

Represents virtual channel or a list of virtual channels.

property name

Specifies the name of the virtual channel this object represents.

Type:

str

property channel_names

Specifies the unflattened list of the virtual channels.

Type:

List[str]

property chan_type

Indicates the type of the virtual channel.

Type:

nidaqmx.constants.ChannelType

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 physical_channel

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

property sync_unlock_behavior

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

Type:

nidaqmx.constants.SyncUnlockBehavior

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.

class nidaqmx.task.channels.AIChannel(task_handle, virtual_or_physical_name, interpreter)

Bases: 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_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.

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_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_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_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_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.

Type:

nidaqmx.constants.SoundPressureUnits

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

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.

Type:

nidaqmx.task.channels.Channel

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_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_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_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_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_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.

Type:

nidaqmx.constants.VoltageUnits

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.

Type:

nidaqmx.constants.PowerIdleOutputBehavior

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.

Type:

nidaqmx.constants.PowerOutputState

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.

Type:

nidaqmx.constants.Sense

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

property ai_rtd_r_0

Deprecated since version 0.7.0: Use ai_rtd_r0 instead.

property ai_sound_pressured_b_ref

Deprecated since version 0.7.0: Use ai_sound_pressure_db_ref instead.

property ai_thrmstr_r_1

Deprecated since version 0.7.0: Use ai_thrmstr_r1 instead.

property ai_acceld_b_ref

Deprecated since version 0.7.0: Use ai_accel_db_ref instead.

property ai_voltaged_b_ref

Deprecated since version 0.7.0: Use ai_voltage_db_ref instead.

property ai_velocity_iepe_sensord_b_ref

Deprecated since version 0.7.0: Use ai_velocity_iepe_sensor_db_ref instead.

class nidaqmx.task.channels.AOChannel(task_handle, virtual_or_physical_name, interpreter)

Bases: Channel

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

property ao_common_mode_offset

Specifies the common-mode offset of the AO channel. Use the property only when Terminal Configuration is set to Differential.

Type:

float

property ao_current_units

Specifies in what units to generate current on the channel. Write data to the channel in the units you select.

Type:

nidaqmx.constants.CurrentUnits

property ao_custom_scale

Specifies the name of a custom scale for the channel.

Type:

nidaqmx.system.scale.Scale

property ao_dac_offset_ext_src

Specifies the source of the DAC offset voltage if ao_dac_offset_src is SourceSelection.EXTERNAL. The valid sources for this signal vary by device.

Type:

str

property ao_dac_offset_src

Specifies the source of the DAC offset voltage. The value of this voltage source determines the full-scale value of the DAC.

Type:

nidaqmx.constants.SourceSelection

property ao_dac_offset_val

Specifies in volts the value of the DAC offset voltage. To achieve best accuracy, the DAC offset value should be hand calibrated.

Type:

float

property ao_dac_ref_allow_conn_to_gnd

Specifies whether to allow grounding the internal DAC reference at run time. You must set this property to True and set ao_dac_ref_src to SourceSelection.INTERNAL before you can set ao_dac_ref_conn_to_gnd to True.

Type:

bool

property ao_dac_ref_conn_to_gnd

Specifies whether to ground the internal DAC reference. Grounding the internal DAC reference has the effect of grounding all analog output channels and stopping waveform generation across all analog output channels regardless of whether the channels belong to the current task. You can ground the internal DAC reference only when ao_dac_ref_src is SourceSelection.INTERNAL and ao_dac_ref_allow_conn_to_gnd is True.

Type:

bool

property ao_dac_ref_ext_src

Specifies the source of the DAC reference voltage if ao_dac_ref_src is SourceSelection.EXTERNAL. The valid sources for this signal vary by device.

Type:

str

property ao_dac_ref_src

Specifies the source of the DAC reference voltage. The value of this voltage source determines the full-scale value of the DAC.

Type:

nidaqmx.constants.SourceSelection

property ao_dac_ref_val

Specifies in volts the value of the DAC reference voltage. This voltage determines the full-scale range of the DAC. Smaller reference voltages result in smaller ranges, but increased resolution.

Type:

float

property ao_dac_rng_high

Specifies the upper limit of the output 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 ao_dac_rng_low

Specifies the lower limit of the output 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 ao_data_xfer_mech

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

property ao_data_xfer_req_cond

nidaqmx.constants.OutputDataTransferCondition: Specifies under what condition to transfer data from the buffer to the onboard memory of the device.

property ao_dev_scaling_coeff

Indicates the coefficients of a linear equation that NI-DAQmx uses to scale values from a voltage to the native format of the device. Each element of the list corresponds to a term of the equation. The first element of the list corresponds to the y-intercept, and the second element corresponds to the slope. Scaling coefficients do not account for any custom scales that may be applied to the channel.

Type:

List[float]

property ao_enhanced_image_rejection_enable

Specifies whether to enable the DAC interpolation filter. Disable the interpolation filter to improve DAC signal-to- noise ratio at the expense of degraded image rejection.

Type:

bool

property ao_filter_delay

Specifies the amount of time between when the sample is written by the host device and when the sample is output by the DAC. This value is in the units you specify with ao_filter_delay_units.

Type:

float

property ao_filter_delay_adjustment

Specifies an additional amount of time to wait between when the sample is written by the host device and when the sample is output by the DAC. This delay adjustment is in addition to the value indicated by ao_filter_delay. This delay adjustment is in the units you specify with ao_filter_delay_units.

Type:

float

property ao_filter_delay_units

Specifies the units of ao_filter_delay and ao_filter_delay_adjustment.

Type:

nidaqmx.constants.DigitalWidthUnits

property ao_func_gen_amplitude

Specifies the zero-to-peak amplitude of the waveform to generate in volts. Zero and negative values are valid.

Type:

float

property ao_func_gen_fm_deviation

Specifies the FM deviation in hertz per volt when ao_func_gen_modulation_type is ModulationType.FM.

Type:

float

property ao_func_gen_freq

Specifies the frequency of the waveform to generate in hertz.

Type:

float

property ao_func_gen_modulation_type

Specifies if the device generates a modulated version of the waveform using the original waveform as a carrier and input from an external terminal as the signal.

Type:

nidaqmx.constants.ModulationType

property ao_func_gen_offset

Specifies the voltage offset of the waveform to generate.

Type:

float

property ao_func_gen_square_duty_cycle

Specifies the square wave duty cycle of the waveform to generate.

Type:

float

property ao_func_gen_start_phase

Specifies the starting phase in degrees of the waveform to generate.

Type:

float

property ao_func_gen_type

Specifies the kind of the waveform to generate.

Type:

nidaqmx.constants.FuncGenType

property ao_gain

Specifies in decibels the gain factor to apply to the channel.

Type:

float

property ao_idle_output_behavior

Specifies the state of the channel when no generation is in progress.

Type:

nidaqmx.constants.AOIdleOutputBehavior

property ao_load_impedance

Specifies in ohms the load impedance connected to the analog output channel.

Type:

float

property ao_max

Specifies the maximum value you expect to generate. The value is in the units you specify with a units property. If you try to write a value larger than the maximum value, NI- DAQmx generates an error. NI-DAQmx might coerce this value to a smaller value if other task settings restrict the device from generating the desired maximum.

Type:

float

property ao_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 ao_min

Specifies the minimum value you expect to generate. The value is in the units you specify with a units property. If you try to write a value smaller than the minimum value, NI- DAQmx generates an error. NI-DAQmx might coerce this value to a larger value if other task settings restrict the device from generating the desired minimum.

Type:

float

property ao_output_impedance

Specifies in ohms the impedance of the analog output stage of the device.

Type:

float

property ao_output_type

Indicates whether the channel generates voltage, current, or a waveform.

Type:

nidaqmx.constants.UsageTypeAO

property ao_reglitch_enable

Specifies whether to enable reglitching. The output of a DAC normally glitches whenever the DAC is updated with a new value. The amount of glitching differs from code to code and is generally largest at major code transitions. Reglitching generates uniform glitch energy at each code transition and provides for more uniform glitches. Uniform glitch energy makes it easier to filter out the noise introduced from glitching during spectrum analysis.

Type:

bool

property ao_resolution

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

Type:

float

property ao_resolution_units

Specifies the units of ao_resolution.

Type:

nidaqmx.constants.ResolutionType

property ao_term_cfg

Specifies the terminal configuration of the channel.

Type:

nidaqmx.constants.TerminalConfiguration

property ao_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 ao_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 ao_use_only_on_brd_mem

Specifies whether to write samples directly to the onboard memory of the device, bypassing the memory buffer. Generally, you cannot update onboard memory directly after you start the task. Onboard memory includes data FIFOs.

Type:

bool

property ao_voltage_current_limit

Specifies the current limit, in amperes, for the voltage channel.

Type:

float

property ao_voltage_units

Specifies in what units to generate voltage on the channel. Write data to the channel in the units you select.

Type:

nidaqmx.constants.VoltageUnits

class nidaqmx.task.channels.CIChannel(task_handle, virtual_or_physical_name, interpreter)

Bases: Channel

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

property ci_ang_encoder_initial_angle

Specifies the starting angle of the encoder. This value is in the units you specify with ci_ang_encoder_units.

Type:

float

property ci_ang_encoder_pulses_per_rev

Specifies the number of pulses the encoder generates per revolution. This value is the number of pulses on either signal A or signal B, not the total number of pulses on both signal A and signal B.

Type:

int

property ci_ang_encoder_units

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

Type:

nidaqmx.constants.AngleUnits

property ci_count

Indicates the current value of the count register.

Type:

int

property ci_count_edges_active_edge

Specifies on which edges to increment or decrement the counter.

Type:

nidaqmx.constants.Edge

property ci_count_edges_count_dir_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_count_edges_count_dir_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_count_edges_count_dir_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_count_edges_count_dir_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_count_edges_count_dir_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_count_edges_count_dir_hyst

Specifies a hysteresis level applied to the ci_count_edges_count_dir_thresh_voltage. The source signal must fall below ci_count_edges_count_dir_thresh_voltage minus the hysteresis before a change in count direction occurs.

Type:

float

property ci_count_edges_count_dir_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_count_edges_count_dir_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_count_edges_count_dir_thresh_voltage

Specifies the voltage level applied to the Count Direction terminal. When the signal is above this threshold, the counter counts up. When the signal is below this threshold, the counter counts down.

Type:

float

property ci_count_edges_count_reset_active_edge

Specifies on which edge of the signal to reset the count.

Type:

nidaqmx.constants.Edge

property ci_count_edges_count_reset_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_count_edges_count_reset_dig_fltr_min_pulse_width

Specifies the minimum pulse width the filter recognizes.

Type:

float

property ci_count_edges_count_reset_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_count_edges_count_reset_dig_fltr_timebase_src

Specifies the input of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_count_edges_count_reset_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_count_edges_count_reset_enable

Specifies whether to reset the count on the active edge specified with ci_count_edges_count_reset_term.

Type:

bool

property ci_count_edges_count_reset_hyst

Specifies a hysteresis level applied to ci_count_edges_count_reset_thresh_voltage. When ci_count_edges_count_reset_active_edge is rising, the source signal must first fall below ci_count_edges_count_reset_thresh_voltage minus the hysteresis before a rising edge is detected at ci_count_edges_count_reset_thresh_voltage. When ci_count_edges_count_reset_active_edge is falling, the source signal must first rise above ci_count_edges_count_reset_thresh_voltage plus the hysteresis before a falling edge is detected at ci_count_edges_count_reset_thresh_voltage.

Type:

float

property ci_count_edges_count_reset_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_count_edges_count_reset_reset_cnt

Specifies the value to reset the count to.

Type:

int

property ci_count_edges_count_reset_term

Specifies the input terminal of the signal to reset the count.

Type:

str

property ci_count_edges_count_reset_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_count_edges_count_reset_thresh_voltage

Specifies the voltage level at which to recognize the counter reset event.

Type:

float

property ci_count_edges_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_count_edges_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_count_edges_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_count_edges_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_count_edges_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_count_edges_dir

Specifies whether to increment or decrement the counter on each edge.

Type:

nidaqmx.constants.CountDirection

property ci_count_edges_dir_term

Specifies the source terminal of the digital signal that controls the count direction if ci_count_edges_dir is CountDirection1.EXTERNAL_SOURCE.

Type:

str

property ci_count_edges_gate_dig_fltr_enable

Specifies whether to apply the pulse width filter to the gate input signal.

Type:

bool

property ci_count_edges_gate_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the digital filter recognizes.

Type:

float

property ci_count_edges_gate_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_count_edges_gate_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_count_edges_gate_enable

Specifies whether to enable the functionality to gate the counter input signal for a count edges measurement.

Type:

bool

property ci_count_edges_gate_hyst

Specifies a hysteresis level applied to the ci_count_edges_gate_thresh_voltage. When ci_count_edges_gate_when is High, the source signal must fall below ci_count_edges_gate_thresh_voltage minus the hysteresis before the counter resumes counting. When ci_count_edges_gate_when is Low, the source signal must rise above ci_count_edges_gate_thresh_voltage plus the hysteresis before the counter resumes counting.

Type:

float

property ci_count_edges_gate_logic_lvl_behavior

Specifies the logic level behavior on the gate input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_count_edges_gate_term

Specifies the gate terminal.

Type:

str

property ci_count_edges_gate_term_cfg

Specifies the gate terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_count_edges_gate_thresh_voltage

Specifies the voltage level at which to recognize the counter gate signal.

Type:

float

property ci_count_edges_gate_when

Specifies whether the counter gates input pulses while the signal is high or low.

Type:

nidaqmx.constants.Level

property ci_count_edges_hyst

Specifies a hysteresis level to apply to ci_count_edges_thresh_voltage. When ci_count_edges_active_edge is rising, the source signal must first fall below ci_count_edges_thresh_voltage minus the hysteresis before a rising edge is detected at ci_count_edges_thresh_voltage. When ci_count_edges_active_edge is falling, the source signal must first rise above ci_count_edges_thresh_voltage plus the hysteresis before a falling edge is detected at ci_count_edges_thresh_voltage.

Type:

float

property ci_count_edges_initial_cnt

Specifies the starting value from which to count.

Type:

int

property ci_count_edges_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_count_edges_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_count_edges_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_count_edges_thresh_voltage

Specifies the voltage level at which to recognize waveform repetitions. 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 ci_ctr_timebase_active_edge

Specifies whether a timebase cycle is from rising edge to rising edge or from falling edge to falling edge.

Type:

nidaqmx.constants.Edge

property ci_ctr_timebase_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_ctr_timebase_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_ctr_timebase_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_ctr_timebase_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_ctr_timebase_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_ctr_timebase_master_timebase_div

Specifies the divisor for an external counter timebase. You can divide the counter timebase in order to measure slower signals without causing the count register to roll over.

Type:

int

property ci_ctr_timebase_rate

Specifies in Hertz the frequency of the counter timebase. Specifying the rate of a counter timebase allows you to take measurements in terms of time or frequency rather than in ticks of the timebase. If you use an external timebase and do not specify the rate, you can take measurements only in terms of ticks of the timebase.

Type:

float

property ci_ctr_timebase_src

Specifies the terminal of the timebase to use for the counter.

Type:

str

property ci_custom_scale

Specifies the name of a custom scale for the channel.

Type:

nidaqmx.system.scale.Scale

property ci_data_xfer_mech

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

property ci_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 ci_dup_count_prevention

Specifies whether to enable duplicate count prevention for the channel. Duplicate count prevention is enabled by default. Setting ci_prescaler disables duplicate count prevention unless you explicitly enable it.

Type:

bool

property ci_duty_cycle_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_duty_cycle_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the digital filter recognizes.

Type:

float

property ci_duty_cycle_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_duty_cycle_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_duty_cycle_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_duty_cycle_starting_edge

Specifies which edge of the input signal to begin the duty cycle measurement.

Type:

nidaqmx.constants.Edge

property ci_duty_cycle_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_duty_cycle_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_encoder_a_input_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_encoder_a_input_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_encoder_a_input_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_encoder_a_input_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_encoder_a_input_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_encoder_a_input_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_encoder_a_input_term

Specifies the terminal to which signal A is connected.

Type:

str

property ci_encoder_a_input_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_encoder_b_input_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_encoder_b_input_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_encoder_b_input_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_encoder_b_input_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_encoder_b_input_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_encoder_b_input_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_encoder_b_input_term

Specifies the terminal to which signal B is connected.

Type:

str

property ci_encoder_b_input_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_encoder_decoding_type

Specifies how to count and interpret the pulses the encoder generates on signal A and signal B. EncoderType2.X_1, EncoderType2.X_2, and EncoderType2.X_4 are valid for quadrature encoders only. EncoderType2.TWO_PULSE_COUNTING is valid for two- pulse encoders only.

Type:

nidaqmx.constants.EncoderType

property ci_encoder_z_index_enable

Specifies whether to use Z indexing for the channel.

Type:

bool

property ci_encoder_z_index_phase

Specifies the states at which signal A and signal B must be while signal Z is high for NI-DAQmx to reset the measurement. If signal Z is never high while signal A and signal B are high, for example, you must choose a phase other than EncoderZIndexPhase1.AHIGH_BHIGH.

Type:

nidaqmx.constants.EncoderZIndexPhase

property ci_encoder_z_index_val

Specifies the value to which to reset the measurement when signal Z is high and signal A and signal B are at the states you specify with ci_encoder_z_index_phase. Specify this value in the units of the measurement.

Type:

float

property ci_encoder_z_input_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_encoder_z_input_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_encoder_z_input_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_encoder_z_input_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_encoder_z_input_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_encoder_z_input_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_encoder_z_input_term

Specifies the terminal to which signal Z is connected.

Type:

str

property ci_encoder_z_input_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_filter_delay

Indicates the amount of time between when the input signal transitions and when the filtered sample is read by the host device. This value is in the units specified with ci_filter_delay_units.

Type:

float

property ci_filter_delay_units

Specifies the units of ci_filter_delay.

Type:

nidaqmx.constants.DigitalWidthUnits

property ci_filter_enable

Specifies the corresponding filter enable/disable state.

Type:

bool

property ci_filter_freq

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

Type:

float

property ci_filter_order

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

Type:

int

property ci_filter_response

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

Type:

nidaqmx.constants.FilterResponse

property ci_freq_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_freq_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_freq_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_freq_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_freq_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_freq_div

Specifies the value by which to divide the input signal if ci_freq_meas_meth is CounterFrequencyMethod.LARGE_RANGE_2_COUNTERS. The larger the divisor, the more accurate the measurement. However, too large a value could cause the count register to roll over, which results in an incorrect measurement.

Type:

int

property ci_freq_enable_averaging

Specifies whether to enable averaging mode for Sample Clock-timed frequency measurements.

Type:

bool

property ci_freq_hyst

Specifies a hysteresis level to apply to ci_freq_thresh_voltage. When ci_freq_starting_edge is rising, the source signal must first fall below ci_freq_thresh_voltage minus the hysteresis before a rising edge is detected at ci_freq_thresh_voltage. When ci_freq_starting_edge is falling, the source signal must first rise above ci_freq_thresh_voltage plus the hysteresis before a falling edge is detected at ci_freq_thresh_voltage.

Type:

float

property ci_freq_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_freq_meas_meth

Specifies the method to use to measure the frequency of the signal.

Type:

nidaqmx.constants.CounterFrequencyMethod

property ci_freq_meas_time

Specifies in seconds the length of time to measure the frequency of the signal if ci_freq_meas_meth is CounterFrequencyMethod.HIGH_FREQUENCY_2_COUNTERS. Measurement accuracy increases with increased measurement time and with increased signal frequency. If you measure a high-frequency signal for too long, however, the count register could roll over, which results in an incorrect measurement.

Type:

float

property ci_freq_starting_edge

Specifies between which edges to measure the frequency of the signal.

Type:

nidaqmx.constants.Edge

property ci_freq_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_freq_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_freq_thresh_voltage

Specifies the voltage level at which to recognize waveform repetitions. 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 ci_freq_units

Specifies the units to use to return frequency measurements.

Type:

nidaqmx.constants.FrequencyUnits

property ci_gps_sync_method

Specifies the method to use to synchronize the counter to a GPS receiver.

Type:

nidaqmx.constants.GpsSignalType

property ci_gps_sync_src

Specifies the terminal to which the GPS synchronization signal is connected.

Type:

str

property ci_lin_encoder_dist_per_pulse

Specifies the distance to measure for each pulse the encoder generates on signal A or signal B. This value is in the units you specify with ci_lin_encoder_units.

Type:

float

property ci_lin_encoder_initial_pos

Specifies the position of the encoder when the measurement begins. This value is in the units you specify with ci_lin_encoder_units.

Type:

float

property ci_lin_encoder_units

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

Type:

nidaqmx.constants.LengthUnits

property ci_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 hardware can measure with the current settings.

Type:

float

property ci_max_meas_period

Specifies the maximum period (in seconds) in which the device will recognize signals. For frequency measurements, a signal with a higher period than the one set in this property will return 0 Hz. For duty cycle, the device will return 0 or 1 depending on the state of the line during the max defined period of time. Period measurements will return NaN. Pulse width measurement will return zero.

Type:

float

property ci_meas_type

Indicates the measurement to take with the channel.

Type:

nidaqmx.constants.UsageTypeCI

property ci_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 ci_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 hardware can measure with the current settings.

Type:

float

property ci_num_possibly_invalid_samps

Indicates the number of samples that the device might have overwritten before it could transfer them to the buffer.

Type:

int

property ci_output_state

Indicates the current state of the out terminal of the counter.

Type:

nidaqmx.constants.Level

property ci_period_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_period_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_period_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_period_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_period_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_period_div

Specifies the value by which to divide the input signal if ci_period_meas_meth is CounterFrequencyMethod.LARGE_RANGE_2_COUNTERS. The larger the divisor, the more accurate the measurement. However, too large a value could cause the count register to roll over, which results in an incorrect measurement.

Type:

int

property ci_period_enable_averaging

Specifies whether to enable averaging mode for Sample Clock-timed period measurements.

Type:

bool

property ci_period_hyst

Specifies a hysteresis level to apply to ci_period_thresh_voltage. When ci_period_starting_edge is rising, the source signal must first fall below ci_period_thresh_voltage minus the hysteresis before a rising edge is detected at ci_period_thresh_voltage. When ci_period_starting_edge is falling, the source signal must first rise above ci_period_thresh_voltage plus the hysteresis before a falling edge is detected at ci_period_thresh_voltage.

Type:

float

property ci_period_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_period_meas_meth

Specifies the method to use to measure the period of the signal.

Type:

nidaqmx.constants.CounterFrequencyMethod

property ci_period_meas_time

Specifies in seconds the length of time to measure the period of the signal if ci_period_meas_meth is CounterFrequencyMethod.HIGH_FREQUENCY_2_COUNTERS. Measurement accuracy increases with increased measurement time and with increased signal frequency. If you measure a high-frequency signal for too long, however, the count register could roll over, which results in an incorrect measurement.

Type:

float

property ci_period_starting_edge

Specifies between which edges to measure the period of the signal.

Type:

nidaqmx.constants.Edge

property ci_period_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_period_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_period_thresh_voltage

Specifies the voltage level at which to recognize waveform repetitions. 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 ci_period_units

Specifies the unit to use to return period measurements.

Type:

nidaqmx.constants.TimeUnits

property ci_prescaler

Specifies the divisor to apply to the signal you connect to the counter source terminal. Scaled data that you read takes this setting into account. You should use a prescaler only when you connect an external signal to the counter source terminal and when that signal has a higher frequency than the fastest onboard timebase. Setting this value disables duplicate count prevention unless you explicitly set ci_dup_count_prevention to True.

Type:

int

property ci_pulse_freq_dig_fltr_enable

Specifies whether to apply a digital filter to the signal to measure.

Type:

bool

property ci_pulse_freq_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_pulse_freq_dig_fltr_timebase_rate

Specifies in hertz the rate of the digital filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_pulse_freq_dig_fltr_timebase_src

Specifies the terminal of the signal to use as the timebase of the digital filter.

Type:

str

property ci_pulse_freq_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_pulse_freq_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_pulse_freq_starting_edge

Specifies on which edge of the input signal to begin pulse measurement.

Type:

nidaqmx.constants.Edge

property ci_pulse_freq_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_pulse_freq_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_pulse_freq_units

Specifies the units to use to return pulse specifications in terms of frequency.

Type:

nidaqmx.constants.FrequencyUnits

property ci_pulse_ticks_dig_fltr_enable

Specifies whether to apply a digital filter to the signal to measure.

Type:

bool

property ci_pulse_ticks_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_pulse_ticks_dig_fltr_timebase_rate

Specifies in hertz the rate of the digital filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_pulse_ticks_dig_fltr_timebase_src

Specifies the terminal of the signal to use as the timebase of the digital filter.

Type:

str

property ci_pulse_ticks_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_pulse_ticks_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_pulse_ticks_starting_edge

Specifies on which edge of the input signal to begin pulse measurement.

Type:

nidaqmx.constants.Edge

property ci_pulse_ticks_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_pulse_ticks_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_pulse_time_dig_fltr_enable

Specifies whether to apply a digital filter to the signal to measure.

Type:

bool

property ci_pulse_time_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_pulse_time_dig_fltr_timebase_rate

Specifies in hertz the rate of the digital filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_pulse_time_dig_fltr_timebase_src

Specifies the terminal of the signal to use as the timebase of the digital filter.

Type:

str

property ci_pulse_time_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_pulse_time_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_pulse_time_starting_edge

Specifies on which edge of the input signal to begin pulse measurement.

Type:

nidaqmx.constants.Edge

property ci_pulse_time_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_pulse_time_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_pulse_time_units

Specifies the units to use to return pulse specifications in terms of high time and low time.

Type:

nidaqmx.constants.TimeUnits

property ci_pulse_width_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_pulse_width_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_pulse_width_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_pulse_width_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_pulse_width_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_pulse_width_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_pulse_width_starting_edge

Specifies on which edge of the input signal to begin each pulse width measurement.

Type:

nidaqmx.constants.Edge

property ci_pulse_width_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_pulse_width_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_pulse_width_units

Specifies the units to use to return pulse width measurements.

Type:

nidaqmx.constants.TimeUnits

property ci_samp_clk_overrun_behavior

Specifies the counter behavior when data is read but a new value was not detected during a sample clock.

Type:

nidaqmx.constants.SampClkOverrunBehavior

property ci_samp_clk_overrun_sentinel_val

Specifies the sentinel value returned when the No New Sample Behavior is set to Sentinel Value.

Type:

int

property ci_semi_period_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_semi_period_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_semi_period_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_semi_period_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_semi_period_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_semi_period_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_semi_period_starting_edge

Specifies on which edge of the input signal to begin semi-period measurement. Semi-period measurements alternate between high time and low time, starting on this edge.

Type:

nidaqmx.constants.Edge

property ci_semi_period_term

Specifies the input terminal of the signal to measure.

Type:

str

property ci_semi_period_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_semi_period_units

Specifies the units to use to return semi-period measurements.

Type:

nidaqmx.constants.TimeUnits

property ci_tc_reached

Indicates whether the counter rolled over. When you query this property, NI-DAQmx resets it to False.

Type:

bool

property ci_thresh_voltage

Specifies the digital threshold value in Volts for high and low input transitions. Some devices do not support this for differential channels.

Type:

float

property ci_timestamp_initial_seconds

Specifies the number of seconds that elapsed since the beginning of the current year. This value is ignored if ci_gps_sync_method is GpsSignalType1.IRIGB.

Type:

int

property ci_timestamp_units

Specifies the units to use to return timestamp measurements.

Type:

nidaqmx.constants.TimeUnits

property ci_two_edge_sep_first_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_two_edge_sep_first_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_two_edge_sep_first_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_two_edge_sep_first_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_two_edge_sep_first_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_two_edge_sep_first_edge

Specifies on which edge of the first signal to start each measurement.

Type:

nidaqmx.constants.Edge

property ci_two_edge_sep_first_logic_lvl_behavior

Specifies the logic level behavior on the input line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_two_edge_sep_first_term

Specifies the source terminal of the digital signal that starts each measurement.

Type:

str

property ci_two_edge_sep_first_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_two_edge_sep_second_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_two_edge_sep_second_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property ci_two_edge_sep_second_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_two_edge_sep_second_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_two_edge_sep_second_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property ci_two_edge_sep_second_edge

Specifies on which edge of the second signal to stop each measurement.

Type:

nidaqmx.constants.Edge

property ci_two_edge_sep_second_logic_lvl_behavior

Specifies the logic level behavior on the count reset line.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_two_edge_sep_second_term

Specifies the source terminal of the digital signal that stops each measurement.

Type:

str

property ci_two_edge_sep_second_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_two_edge_sep_units

Specifies the units to use to return two-edge separation measurements from the channel.

Type:

nidaqmx.constants.TimeUnits

property ci_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 ci_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 ci_velocity_a_input_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_velocity_a_input_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the digital filter recognizes.

Type:

float

property ci_velocity_a_input_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_velocity_a_input_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_velocity_a_input_logic_lvl_behavior

Specifies the logic level behavior of the input terminal.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_velocity_a_input_term

Specifies the terminal to which signal A is connected.

Type:

str

property ci_velocity_a_input_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_velocity_ang_encoder_pulses_per_rev

Specifies the number of pulses the encoder generates per revolution. This value is the number of pulses on either signal A or signal B, not the total number of pulses on both signal A and signal B.

Type:

int

property ci_velocity_ang_encoder_units

Specifies the units to use to return angular velocity counter measurements.

Type:

nidaqmx.constants.AngularVelocityUnits

property ci_velocity_b_input_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property ci_velocity_b_input_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the digital filter recognizes.

Type:

float

property ci_velocity_b_input_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property ci_velocity_b_input_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property ci_velocity_b_input_logic_lvl_behavior

Specifies the logic level behavior of the input terminal.

Type:

nidaqmx.constants.LogicLvlBehavior

property ci_velocity_b_input_term

Specifies the terminal to which signal B is connected.

Type:

str

property ci_velocity_b_input_term_cfg

Specifies the input terminal configuration.

Type:

nidaqmx.constants.TerminalConfiguration

property ci_velocity_div

Specifies the value by which to divide the input signal.

Type:

int

property ci_velocity_encoder_decoding_type

Specifies how to count and interpret the pulses the encoder generates on signal A and signal B. X1, X2, and X4 are valid for quadrature encoders only. Two Pulse Counting is valid for two-pulse encoders only.

Type:

nidaqmx.constants.EncoderType

property ci_velocity_lin_encoder_dist_per_pulse

Specifies the distance to measure for each pulse the encoder generates on signal A or signal B. This value is in the units you specify in CI.Velocity.LinEncoder.DistUnits.

Type:

float

property ci_velocity_lin_encoder_units

Specifies the units to use to return linear encoder velocity measurements from the channel.

Type:

nidaqmx.constants.VelocityUnits

property ci_velocity_meas_time

Specifies in seconds the length of time to measure the velocity of the signal.

Type:

float

class nidaqmx.task.channels.COChannel(task_handle, virtual_or_physical_name, interpreter)

Bases: Channel

Represents one or more counter output virtual channels and their properties.

property co_auto_incr_cnt

Specifies a number of timebase ticks by which to increase the time spent in the idle state for each successive pulse.

Type:

int

property co_constrained_gen_mode

Specifies constraints to apply when the counter generates pulses. Constraining the counter reduces the device resources required for counter operation. Constraining the counter can also allow additional analog or counter tasks on the device to run concurrently. For continuous counter tasks, NI-DAQmx consumes no device resources when the counter is constrained. For finite counter tasks, resource use increases with the frequency regardless of the constraint mode. However, fixed frequency constraints significantly reduce resource usage, and fixed duty cycle constraint marginally reduces it.

Type:

nidaqmx.constants.ConstrainedGenMode

property co_count

Indicates the current value of the count register.

Type:

int

property co_ctr_timebase_active_edge

Specifies whether a timebase cycle is from rising edge to rising edge or from falling edge to falling edge.

Type:

nidaqmx.constants.Edge

property co_ctr_timebase_dig_fltr_enable

Specifies whether to apply the pulse width filter to the signal.

Type:

bool

property co_ctr_timebase_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes.

Type:

float

property co_ctr_timebase_dig_fltr_timebase_rate

Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property co_ctr_timebase_dig_fltr_timebase_src

Specifies the input terminal of the signal to use as the timebase of the pulse width filter.

Type:

str

property co_ctr_timebase_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property co_ctr_timebase_master_timebase_div

Specifies the divisor for an external counter timebase. You can divide the counter timebase in order to generate slower signals without causing the count register to roll over.

Type:

int

property co_ctr_timebase_rate

Specifies in Hertz the frequency of the counter timebase. Specifying the rate of a counter timebase allows you to define output pulses in seconds rather than in ticks of the timebase. If you use an external timebase and do not specify the rate, you can define output pulses only in ticks of the timebase.

Type:

float

property co_ctr_timebase_src

Specifies the terminal of the timebase to use for the counter. Typically, NI-DAQmx uses one of the internal counter timebases when generating pulses. Use this property to specify an external timebase and produce custom pulse widths that are not possible using the internal timebases.

Type:

str

property co_data_xfer_mech

nidaqmx.constants.DataTransferActiveTransferMode: Specifies the data transfer mode for the device. For buffered operations, use DMA or USB Bulk. For non-buffered operations, use Polled.

property co_data_xfer_req_cond

nidaqmx.constants.OutputDataTransferCondition: Specifies under what condition to transfer data from the buffer to the onboard memory of the device.

property co_enable_initial_delay_on_retrigger

Specifies whether to apply the initial delay to retriggered pulse trains.

Type:

bool

property co_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 co_output_state

Indicates the current state of the output terminal of the counter.

Type:

nidaqmx.constants.Level

property co_output_type

Indicates how to define pulses generated on the channel.

Type:

nidaqmx.constants.UsageTypeCO

property co_prescaler

Specifies the divisor to apply to the signal you connect to the counter source terminal. Pulse generations defined by frequency or time take this setting into account, but pulse generations defined by ticks do not. You should use a prescaler only when you connect an external signal to the counter source terminal and when that signal has a higher frequency than the fastest onboard timebase.

Type:

int

property co_pulse_done

Indicates if the task completed pulse generation. Use this value for retriggerable pulse generation when you need to determine if the device generated the current pulse. For retriggerable tasks, when you query this property, NI-DAQmx resets it to False.

Type:

bool

property co_pulse_duty_cyc

Specifies the duty cycle of the pulses. The duty cycle of a signal is the width of the pulse divided by period. NI- DAQmx uses this ratio and the pulse frequency to determine the width of the pulses and the delay between pulses.

Type:

float

property co_pulse_freq

Specifies the frequency of the pulses to generate. This value is in the units you specify with co_pulse_freq_units or when you create the channel.

Type:

float

property co_pulse_freq_initial_delay

Specifies in seconds the amount of time to wait before generating the first pulse.

Type:

float

property co_pulse_freq_units

Specifies the units in which to define pulse frequency.

Type:

nidaqmx.constants.FrequencyUnits

property co_pulse_high_ticks

Specifies the number of ticks the pulse is high.

Type:

int

property co_pulse_high_time

Specifies the amount of time that the pulse is at a high voltage. This value is in the units you specify with co_pulse_time_units or when you create the channel.

Type:

float

property co_pulse_idle_state

Specifies the resting state of the output terminal.

Type:

nidaqmx.constants.Level

property co_pulse_low_ticks

Specifies the number of ticks the pulse is low.

Type:

int

property co_pulse_low_time

Specifies the amount of time that the pulse is at a low voltage. This value is in the units you specify with co_pulse_time_units or when you create the channel.

Type:

float

property co_pulse_term

Specifies on which terminal to generate pulses.

Type:

str

property co_pulse_ticks_initial_delay

Specifies the number of ticks to wait before generating the first pulse.

Type:

int

property co_pulse_time_initial_delay

Specifies in seconds the amount of time to wait before generating the first pulse.

Type:

float

property co_pulse_time_units

Specifies the units in which to define high and low pulse time.

Type:

nidaqmx.constants.TimeUnits

property co_rdy_for_new_val

Indicates whether the counter is ready for new continuous pulse train values.

Type:

bool

property co_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 co_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 co_use_only_on_brd_mem

Specifies whether to write samples directly to the onboard memory of the device, bypassing the memory buffer. Generally, you cannot update onboard memory directly after you start the task. Onboard memory includes data FIFOs.

Type:

bool

class nidaqmx.task.channels.DIChannel(task_handle, virtual_or_physical_name, interpreter)

Bases: Channel

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

property di_acquire_on

nidaqmx.constants.ActiveOrInactiveEdgeSelection: Specifies on which edge of the sample clock to acquire samples.

property di_data_xfer_mech

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

property di_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 di_dig_fltr_enable

Specifies whether to enable the digital filter for the line(s) or port(s). You can enable the filter on a line-by- line basis. You do not have to enable the filter for all lines in a channel.

Type:

bool

property di_dig_fltr_enable_bus_mode

Specifies whether to enable bus mode for digital filtering. If you set this property to True, NI-DAQmx treats all lines that use common filtering settings as a bus. If any line in the bus has jitter, all lines in the bus hold state until the entire bus stabilizes, or until 2 times the minimum pulse width elapses. If you set this property to False, NI-DAQmx filters all lines individually. Jitter in one line does not affect other lines.

Type:

bool

property di_dig_fltr_min_pulse_width

Specifies in seconds the minimum pulse width the filter recognizes as a valid high or low state transition.

Type:

float

property di_dig_fltr_timebase_rate

Specifies in hertz the rate of the digital filter timebase. NI-DAQmx uses this value to compute settings for the filter.

Type:

float

property di_dig_fltr_timebase_src

Specifies the terminal of the signal to use as the timebase of the digital filter.

Type:

str

property di_dig_sync_enable

Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device.

Type:

bool

property di_invert_lines

Specifies whether to invert the lines in the channel. If you set this property to True, the lines are at high logic when off and at low logic when on.

Type:

bool

property di_logic_family

Specifies the logic family to use for acquisition. A logic family corresponds to voltage thresholds that are compatible with a group of voltage standards. Refer to the device documentation for information on the logic high and logic low voltages for these logic families.

Type:

nidaqmx.constants.LogicFamily

property di_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 di_num_lines

Indicates the number of digital lines in the channel.

Type:

int

property di_tristate

Specifies whether to tristate the lines in the channel. If you set this property to True, NI-DAQmx tristates the lines in the channel. If you set this property to False, NI-DAQmx does not modify the configuration of the lines even if the lines were previously tristated. Set this property to False to read lines in other tasks or to read output-only lines.

Type:

bool

property di_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 di_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

class nidaqmx.task.channels.DOChannel(task_handle, virtual_or_physical_name, interpreter)

Bases: Channel

Represents one or more digital output virtual channels and their properties.

property do_data_xfer_mech

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

property do_data_xfer_req_cond

nidaqmx.constants.OutputDataTransferCondition: Specifies under what condition to transfer data from the buffer to the onboard memory of the device.

property do_generate_on

nidaqmx.constants.ActiveOrInactiveEdgeSelection: Specifies on which edge of the sample clock to generate samples.

property do_invert_lines

Specifies whether to invert the lines in the channel. If you set this property to True, the lines are at high logic when off and at low logic when on.

Type:

bool

property do_line_states_done_state

Specifies the state of the lines in a digital output task when the task completes execution.

Type:

nidaqmx.constants.Level

property do_line_states_paused_state

Specifies the state of the lines in a digital output task when the task pauses.

Type:

nidaqmx.constants.Level

property do_line_states_start_state

Specifies the state of the lines in a digital output task when the task starts.

Type:

nidaqmx.constants.Level

property do_logic_family

Specifies the logic family to use for generation. A logic family corresponds to voltage thresholds that are compatible with a group of voltage standards. Refer to the device documentation for information on the logic high and logic low voltages for these logic families.

Type:

nidaqmx.constants.LogicFamily

property do_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 do_num_lines

Indicates the number of digital lines in the channel.

Type:

int

property do_output_drive_type

Specifies the drive type for digital output channels.

Type:

nidaqmx.constants.DigitalDriveType

property do_overcurrent_auto_reenable

Specifies whether to automatically reenable channels after they no longer exceed the current limit specified by do_overcurrent_limit.

Type:

bool

property do_overcurrent_limit

Specifies the current threshold in Amperes for the channel. A value of 0 means the channel observes no limit. Devices can monitor only a finite number of current thresholds simultaneously. If you attempt to monitor additional thresholds, NI-DAQmx returns an error.

Type:

float

property do_overcurrent_reenable_period

Specifies the delay in seconds between the time a channel no longer exceeds the current limit and the reactivation of that channel, if do_overcurrent_auto_reenable is True.

Type:

float

property do_tristate

Specifies whether to stop driving the channel and set it to a high-impedance state. You must commit the task for this setting to take effect.

Type:

bool

property do_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 do_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 do_use_only_on_brd_mem

Specifies whether to write samples directly to the onboard memory of the device, bypassing the memory buffer. Generally, you cannot update onboard memory after you start the task. Onboard memory includes data FIFOs.

Type:

bool