NI DAQMX Channel Attributes Analog Input - ni/grpc-device GitHub Wiki

Channel Attributes - Analog Input

See how to get and set attributes.

DAQmx_AI_Max

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Min

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_CustomScaleName

Data Type: char*
Description: Specifies the name of a custom scale for the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_MeasType

Data Type: int32
Description: Indicates the measurement to take with the analog input channel and in some cases, such as for temperature measurements, the sensor to use.
Restrictions: Not Settable

Valid values

DAQmx_Val_Voltage 10322 Voltage measurement.
DAQmx_Val_VoltageRMS 10350 Voltage RMS measurement.
DAQmx_Val_Current 10134 Current measurement.
DAQmx_Val_CurrentRMS 10351 Current RMS measurement.
DAQmx_Val_Voltage_CustomWithExcitation 10323 Voltage measurement with an excitation source. You can use this measurement type for custom sensors that require excitation, but you must use a custom scale to scale the measured voltage.
DAQmx_Val_Bridge 15908 Measure voltage ratios from a Wheatstone bridge.
DAQmx_Val_Freq_Voltage 10181 Frequency measurement using a frequency to voltage converter.
DAQmx_Val_Resistance 10278 Resistance measurement.
DAQmx_Val_Temp_TC 10303 Temperature measurement using a thermocouple.
DAQmx_Val_Temp_Thrmstr 10302 Temperature measurement using a thermistor.
DAQmx_Val_Temp_RTD 10301 Temperature measurement using an RTD.
DAQmx_Val_Temp_BuiltInSensor 10311 Temperature measurement using a built-in sensor on a terminal block or device. On SCXI modules, for example, this could be the CJC sensor.
DAQmx_Val_Strain_Gage 10300 Strain measurement.
DAQmx_Val_Rosette_Strain_Gage 15980 Strain measurement using a rosette strain gage.
DAQmx_Val_Position_LVDT 10352 Position measurement using an LVDT.
DAQmx_Val_Position_RVDT 10353 Position measurement using an RVDT.
DAQmx_Val_Position_EddyCurrentProximityProbe 14835 Position measurement using an eddy current proximity probe.
DAQmx_Val_Accelerometer 10356 Acceleration measurement using an accelerometer.
DAQmx_Val_Acceleration_Charge 16104 Acceleration measurement using a charge-based sensor.
DAQmx_Val_Acceleration_4WireDCVoltage 16106 Acceleration measurement using a 4 wire DC voltage based sensor.
DAQmx_Val_Velocity_IEPESensor 15966 Velocity measurement using an IEPE Sensor.
DAQmx_Val_Force_Bridge 15899 Force measurement using a bridge-based sensor.
DAQmx_Val_Force_IEPESensor 15895 Force measurement using an IEPE Sensor.
DAQmx_Val_Pressure_Bridge 15902 Pressure measurement using a bridge-based sensor.
DAQmx_Val_SoundPressure_Microphone 10354 Sound pressure measurement using a microphone.
DAQmx_Val_Torque_Bridge 15905 Torque measurement using a bridge-based sensor.
DAQmx_Val_TEDS_Sensor 12531 Measurement type defined by TEDS.
DAQmx_Val_Charge 16105 Charge measurement.

You can get this attribute using:   DAQmxGetChanAttribute

Input Voltage

DAQmx_AI_Voltage_Units

Data Type: int32
Description: Specifies the units to use to return voltage measurements from the channel.

Valid values

DAQmx_Val_Volts 10348 Volts.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_FromTEDS 12516 Units defined by TEDS information associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Voltage_dBRef

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

AC RMS Voltage

DAQmx_AI_Voltage_ACRMS_Units

Data Type: int32
Description: Specifies the units to use to return voltage RMS measurements from the channel.

Valid values

DAQmx_Val_Volts 10348 Volts.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_FromTEDS 12516 Units defined by TEDS information associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Temperature

DAQmx_AI_Temp_Units

Data Type: int32
Description: Specifies the units to use to return temperature measurements from the channel.

Valid values

DAQmx_Val_DegC 10143 Degrees Celsius.
DAQmx_Val_DegF 10144 Degrees Fahrenheit.
DAQmx_Val_Kelvins 10325 Kelvins.
DAQmx_Val_DegR 10145 Degrees Rankine.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Thermocouple

DAQmx_AI_Thrmcpl_Type

Data Type: int32
Description: Specifies the type of thermocouple connected to the channel. Thermocouple types differ in composition and measurement range.

Valid values

DAQmx_Val_J_Type_TC 10072 J-type thermocouple.
DAQmx_Val_K_Type_TC 10073 K-type thermocouple.
DAQmx_Val_N_Type_TC 10077 N-type thermocouple.
DAQmx_Val_R_Type_TC 10082 R-type thermocouple.
DAQmx_Val_S_Type_TC 10085 S-type thermocouple.
DAQmx_Val_T_Type_TC 10086 T-type thermocouple.
DAQmx_Val_B_Type_TC 10047 B-type thermocouple.
DAQmx_Val_E_Type_TC 10055 E-type thermocouple.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmcpl_ScaleType

Data Type: int32
Description: Specifies the method or equation form that the thermocouple scale uses.

Valid values

DAQmx_Val_Polynomial 10449 Scale values by using an Nth order polynomial equation.
DAQmx_Val_Table 10450 Map an array of prescaled values to an array of corresponding scaled values, with all other values scaled proportionally.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmcpl_CJCSrc

Data Type: int32
Description: Indicates the source of cold-junction compensation.
Restrictions: Not Settable

Valid values

DAQmx_Val_BuiltIn 10200 Use a cold-junction compensation channel built into the terminal block.
DAQmx_Val_ConstVal 10116 You must specify the cold-junction temperature.
DAQmx_Val_Chan 10113 Use a channel for cold-junction compensation.

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_Thrmcpl_CJCVal

Data Type: float64
Description: Specifies the temperature of the cold junction if DAQmx_AI_Thrmcpl_CJCSrc is DAQmx_Val_ConstVal. Specify this value in the units of the measurement.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmcpl_CJCChan

Data Type: char*
Description: Indicates the channel that acquires the temperature of the cold junction if DAQmx_AI_Thrmcpl_CJCSrc is DAQmx_Val_Chan. 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.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

RTD

DAQmx_AI_RTD_Type

Data Type: int32
Description: Specifies the type of RTD connected to the channel.

Valid values

DAQmx_Val_Pt3750 12481 Pt3750.
DAQmx_Val_Pt3851 10071 Pt3851.
DAQmx_Val_Pt3911 12482 Pt3911.
DAQmx_Val_Pt3916 10069 Pt3916.
DAQmx_Val_Pt3920 10053 Pt3920.
DAQmx_Val_Pt3928 12483 Pt3928.
DAQmx_Val_Custom 10137 You must use DAQmx_AI_RTD_A, DAQmx_AI_RTD_B, and DAQmx_AI_RTD_C to supply the coefficients for the Callendar-Van Dusen equation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RTD_R0

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Custom

DAQmx_AI_RTD_A

Data Type: float64
Description: Specifies the 'A' constant of the Callendar-Van Dusen equation. NI-DAQmx requires this value when you use a custom RTD.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RTD_B

Data Type: float64
Description: Specifies the 'B' constant of the Callendar-Van Dusen equation. NI-DAQmx requires this value when you use a custom RTD.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RTD_C

Data Type: float64
Description: Specifies the 'C' constant of the Callendar-Van Dusen equation. NI-DAQmx requires this value when you use a custom RTD.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Thermistor

DAQmx_AI_Thrmstr_A

Data Type: float64
Description: Specifies the 'A' constant of the Steinhart-Hart thermistor equation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmstr_B

Data Type: float64
Description: Specifies the 'B' constant of the Steinhart-Hart thermistor equation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmstr_C

Data Type: float64
Description: Specifies the 'C' constant of the Steinhart-Hart thermistor equation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmstr_R1

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Temperature Advanced

DAQmx_AI_ForceReadFromChan

Data Type: bool32
Description: Specifies whether to read from the channel if it is a cold-junction compensation channel. By default, an NI-DAQmx Read function 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Input Current

DAQmx_AI_Current_Units

Data Type: int32
Description: Specifies the units to use to return current measurements from the channel.

Valid values

DAQmx_Val_Amps 10342 Amperes.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_FromTEDS 12516 Units defined by TEDS information associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

AC RMS Current

DAQmx_AI_Current_ACRMS_Units

Data Type: int32
Description: Specifies the units to use to return current RMS measurements from the channel.

Valid values

DAQmx_Val_Amps 10342 Amperes.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_FromTEDS 12516 Units defined by TEDS information associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Strain

DAQmx_AI_Strain_Units

Data Type: int32
Description: Specifies the units to use to return strain measurements from the channel.

Valid values

DAQmx_Val_Strain 10299 Strain.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_StrainGage_ForceReadFromChan

Data Type: bool32
Description: Specifies whether the data is returned by an NI-DAQmx Read function when set on a raw strain channel that is part of a rosette configuration.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Strain Gage

DAQmx_AI_StrainGage_GageFactor

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_StrainGage_PoissonRatio

Data Type: float64
Description: Specifies the ratio of lateral strain to axial strain in the material you are measuring.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_StrainGage_Cfg

Data Type: int32
Description: Specifies the bridge configuration of the strain gages.

Valid values

DAQmx_Val_FullBridgeI 10183 Four active gages with two pairs subjected to equal and opposite strains.
DAQmx_Val_FullBridgeII 10184 Four active gages with two aligned with maximum principal strain and two Poisson gages in adjacent arms.
DAQmx_Val_FullBridgeIII 10185 Four active gages with two aligned with maximum principal strain and two Poisson gages in opposite arms.
DAQmx_Val_HalfBridgeI 10188 Two active gages with one aligned with maximum principal strain and one Poisson gage.
DAQmx_Val_HalfBridgeII 10189 Two active gages with equal and opposite strains.
DAQmx_Val_QuarterBridgeI 10271 Single active gage.
DAQmx_Val_QuarterBridgeII 10272 Single active gage and one dummy gage.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Rosette Strain Gage

DAQmx_AI_RosetteStrainGage_RosetteType

Data Type: int32
Description: Indicates the type of rosette gage.
Restrictions: Not Settable

Valid values

DAQmx_Val_RectangularRosette 15968 A rectangular rosette consists of three strain gages, each separated by a 45 degree angle.
DAQmx_Val_DeltaRosette 15969 A delta rosette consists of three strain gages, each separated by a 60 degree angle.
DAQmx_Val_TeeRosette 15970 A tee rosette consists of two gages oriented at 90 degrees with respect to each other.

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_RosetteStrainGage_Orientation

Data Type: float64
Description: Specifies gage orientation in degrees with respect to the X axis.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RosetteStrainGage_StrainChans

Data Type: char*
Description: Indicates the raw strain channels that comprise the strain rosette.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_RosetteStrainGage_RosetteMeasType

Data Type: int32
Description: Specifies the type of rosette measurement.

Valid values

DAQmx_Val_PrincipalStrain1 15971 The maximum tensile strain coplanar to the surface of the material under stress.
DAQmx_Val_PrincipalStrain2 15972 The minimum tensile strain coplanar to the surface of the material under stress.
DAQmx_Val_PrincipalStrainAngle 15973 The angle at which the principal strains of the rosette occur.
DAQmx_Val_CartesianStrainX 15974 The tensile strain coplanar to the surface of the material under stress in the X coordinate direction.
DAQmx_Val_CartesianStrainY 15975 The tensile strain coplanar to the surface of the material under stress in the Y coordinate direction.
DAQmx_Val_CartesianShearStrainXY 15976 The tensile strain coplanar to the surface of the material under stress in the XY coordinate direction.
DAQmx_Val_MaxShearStrain 15977 The maximum strain coplanar to the cross section of the material under stress.
DAQmx_Val_MaxShearStrainAngle 15978 The angle at which the maximum shear strain of the rosette occurs.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Resistance

DAQmx_AI_Resistance_Units

Data Type: int32
Description: Specifies the units to use to return resistance measurements.

Valid values

DAQmx_Val_Ohms 10384 Ohms.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_FromTEDS 12516 Units defined by TEDS information associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Analog Input Frequency

DAQmx_AI_Freq_Units

Data Type: int32
Description: Specifies the units to use to return frequency measurements from the channel.

Valid values

DAQmx_Val_Hz 10373 Hertz.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Frequency Voltage

DAQmx_AI_Freq_ThreshVoltage

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Freq_Hyst

Data Type: float64
Description: Specifies in volts a window below DAQmx_AI_Freq_ThreshVoltage. The input voltage must pass below DAQmx_AI_Freq_ThreshVoltage minus this value before NI-DAQmx recognizes a waveform repetition at DAQmx_AI_Freq_ThreshVoltage. Hysteresis can improve the measurement accuracy when the signal contains noise or jitter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Analog Position

LVDT

DAQmx_AI_LVDT_Units

Data Type: int32
Description: Specifies the units to use to return linear position measurements from the channel.

Valid values

DAQmx_Val_Meters 10219 Meters.
DAQmx_Val_Inches 10379 Inches.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_LVDT_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the LVDT. This value is in the units you specify with DAQmx_AI_LVDT_SensitivityUnits. Refer to the sensor documentation to determine this value.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_LVDT_SensitivityUnits

Data Type: int32
Description: Specifies the units of DAQmx_AI_LVDT_Sensitivity.

Valid values

DAQmx_Val_mVoltsPerVoltPerMillimeter 12506 mVolts/Volt/mMeter.
DAQmx_Val_mVoltsPerVoltPerMilliInch 12505 mVolts/Volt/0.001 Inch.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

RVDT

DAQmx_AI_RVDT_Units

Data Type: int32
Description: Specifies the units to use to return angular position measurements from the channel.

Valid values

DAQmx_Val_Degrees 10146 Degrees.
DAQmx_Val_Radians 10273 Radians.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RVDT_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the RVDT. This value is in the units you specify with DAQmx_AI_RVDT_SensitivityUnits. Refer to the sensor documentation to determine this value.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RVDT_SensitivityUnits

Data Type: int32
Description: Specifies the units of DAQmx_AI_RVDT_Sensitivity.

Valid values

DAQmx_Val_mVoltsPerVoltPerDegree 12507 mVolts/Volt/Degree.
DAQmx_Val_mVoltsPerVoltPerRadian 12508 mVolts/Volt/Radian.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Eddy Current Proximity Probe

DAQmx_AI_EddyCurrentProxProbe_Units

Data Type: int32
Description: Specifies the units to use to return proximity measurements from the channel.

Valid values

DAQmx_Val_Meters 10219 Meters.
DAQmx_Val_Inches 10379 Inches.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_EddyCurrentProxProbe_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the eddy current proximity probe . This value is in the units you specify with DAQmx_AI_EddyCurrentProxProbe_SensitivityUnits. Refer to the sensor documentation to determine this value.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_EddyCurrentProxProbe_SensitivityUnits

Data Type: int32
Description: Specifies the units of DAQmx_AI_EddyCurrentProxProbe_Sensitivity.

Valid values

DAQmx_Val_mVoltsPerMil 14836 mVolts/mil.
DAQmx_Val_VoltsPerMil 14837 Volts/mil.
DAQmx_Val_mVoltsPerMillimeter 14838 mVolts/mMeter.
DAQmx_Val_VoltsPerMillimeter 14839 Volts/mMeter.
DAQmx_Val_mVoltsPerMicron 14840 mVolts/micron.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Sound Pressure

DAQmx_AI_SoundPressure_MaxSoundPressureLvl

Data Type: float64
Description: 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 DAQmx_AI_Max and DAQmx_AI_Min for the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_SoundPressure_Units

Data Type: int32
Description: Specifies the units to use to return sound pressure measurements from the channel.

Valid values

DAQmx_Val_Pascals 10081 Pascals.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_SoundPressure_dBRef

Data Type: float64
Description: 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 DAQmx_AI_SoundPressure_MaxSoundPressureLvl to a voltage level.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Microphone

DAQmx_AI_Microphone_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the microphone. This value is in mV/Pa. Refer to the sensor documentation to determine this value.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Acceleration

DAQmx_AI_Accel_Units

Data Type: int32
Description: Specifies the units to use to return acceleration measurements from the channel.

Valid values

DAQmx_Val_AccelUnit_g 10186 1 g is approximately equal to 9.81 m/s/s.
DAQmx_Val_MetersPerSecondSquared 12470 Meters per second per second.
DAQmx_Val_InchesPerSecondSquared 12471 Inches per second per second.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Accel_dBRef

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

4 Wire Dc Voltage

DAQmx_AI_Accel_4WireDCVoltage_Sensitivity

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Accel_4WireDCVoltage_SensitivityUnits

Data Type: int32
Description: Specifies the units of AI.Accel.4WireDCVoltage.Sensitivity.

Valid values

DAQmx_Val_mVoltsPerG 12509 mVolts/g.
DAQmx_Val_VoltsPerG 12510 Volts/g.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Accelerometer

DAQmx_AI_Accel_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the accelerometer. This value is in the units you specify with DAQmx_AI_Accel_SensitivityUnits. Refer to the sensor documentation to determine this value.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Accel_SensitivityUnits

Data Type: int32
Description: Specifies the units of DAQmx_AI_Accel_Sensitivity.

Valid values

DAQmx_Val_mVoltsPerG 12509 mVolts/g.
DAQmx_Val_VoltsPerG 12510 Volts/g.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Acceleration Charge

DAQmx_AI_Accel_Charge_Sensitivity

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Accel_Charge_SensitivityUnits

Data Type: int32
Description: Specifies the units of AI.Accel.Charge.Sensitivity.

Valid values

DAQmx_Val_PicoCoulombsPerG 16099 PicoCoulombs per g.
DAQmx_Val_PicoCoulombsPerMetersPerSecondSquared 16100 PicoCoulombs per m/s^2.
DAQmx_Val_PicoCoulombsPerInchesPerSecondSquared 16101 PicoCoulombs per in/s^2.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Analog Velocity

DAQmx_AI_Velocity_Units

Data Type: int32
Description: Specifies in which unit to return velocity measurements from the channel.

Valid values

DAQmx_Val_MetersPerSecond 15959 Meters per second.
DAQmx_Val_InchesPerSecond 15960 Inches per second.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Velocity IEPE Sensor

DAQmx_AI_Velocity_IEPESensor_dBRef

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Velocity_IEPESensor_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the IEPE velocity sensor connected to the channel. Specify this value in the unit indicated by DAQmx_AI_Velocity_IEPESensor_SensitivityUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Velocity_IEPESensor_SensitivityUnits

Data Type: int32
Description: Specifies the units for DAQmx_AI_Velocity_IEPESensor_Sensitivity.

Valid values

DAQmx_Val_MillivoltsPerMillimeterPerSecond 15963 Millivolts per millimeter per second.
DAQmx_Val_MilliVoltsPerInchPerSecond 15964 Millivolts per inch per second.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Force

DAQmx_AI_Force_Units

Data Type: int32
Description: Specifies in which unit to return force or load measurements from the channel.

Valid values

DAQmx_Val_Newtons 15875 Newtons.
DAQmx_Val_Pounds 15876 Pounds.
DAQmx_Val_KilogramForce 15877 Kilograms-force.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Force IEPE Sensor

DAQmx_AI_Force_IEPESensor_Sensitivity

Data Type: float64
Description: Specifies the sensitivity of the IEPE force sensor connected to the channel. Specify this value in the unit indicated by DAQmx_AI_Force_IEPESensor_SensitivityUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Force_IEPESensor_SensitivityUnits

Data Type: int32
Description: Specifies the units for DAQmx_AI_Force_IEPESensor_Sensitivity.

Valid values

DAQmx_Val_mVoltsPerNewton 15891 Millivolts per newton.
DAQmx_Val_mVoltsPerPound 15892 Millivolts per pound.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Pressure

DAQmx_AI_Pressure_Units

Data Type: int32
Description: Specifies in which unit to return pressure measurements from the channel.

Valid values

DAQmx_Val_Pascals 10081 Pascals.
DAQmx_Val_PoundsPerSquareInch 15879 Pounds per square inch.
DAQmx_Val_Bar 15880 Bar.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Torque

DAQmx_AI_Torque_Units

Data Type: int32
Description: Specifies in which unit to return torque measurements from the channel.

Valid values

DAQmx_Val_NewtonMeters 15881 Newton meters.
DAQmx_Val_InchOunces 15882 Ounce-inches.
DAQmx_Val_InchPounds 15883 Pound-inches.
DAQmx_Val_FootPounds 15884 Pound-feet.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Bridge

DAQmx_AI_Bridge_Units

Data Type: int32
Description: Specifies in which unit to return voltage ratios from the channel.

Valid values

DAQmx_Val_VoltsPerVolt 15896 Volts per volt.
DAQmx_Val_mVoltsPerVolt 15897 Millivolts per volt.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.
DAQmx_Val_FromTEDS 12516 Units defined by TEDS information associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Scaling Parameters

DAQmx_AI_Bridge_ElectricalUnits

Data Type: int32
Description: Specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet or calibration certificate uses for electrical values.

Valid values

DAQmx_Val_VoltsPerVolt 15896 Volts per volt.
DAQmx_Val_mVoltsPerVolt 15897 Millivolts per volt.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_PhysicalUnits

Data Type: int32
Description: 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.

Valid values

DAQmx_Val_Newtons 15875 Newtons.
DAQmx_Val_Pounds 15876 Pounds.
DAQmx_Val_KilogramForce 15877 kilograms-force.
DAQmx_Val_Pascals 10081 Pascals.
DAQmx_Val_PoundsPerSquareInch 15879 Pounds per square inch.
DAQmx_Val_Bar 15880 Bar.
DAQmx_Val_NewtonMeters 15881 Newton metres.
DAQmx_Val_InchOunces 15882 Ounce-inches.
DAQmx_Val_InchPounds 15883 Pound-inches.
DAQmx_Val_FootPounds 15884 Pound-feet.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ScaleType

Data Type: int32
Description: Specifies the scaling type to use when scaling electrical values from the sensor to physical units.

Valid values

DAQmx_Val_None 10230 Do not scale electrical values to physical units.
DAQmx_Val_TwoPointLinear 15898 You provide two pairs of electrical values and their corresponding physical values. NI-DAQmx uses those values to calculate the slope and y-intercept of a linear equation and uses that equation to scale electrical values to physical values.
DAQmx_Val_Table 10450 Map an array of electrical values to an array of corresponding physical values, with all other values scaled proportionally. If you specify this scaling type, DAQmx_AI_Max and DAQmx_AI_Min must be within the smallest and largest physical values. For any data outside those endpoints, NI-DAQmx coerces that data to the endpoints.
DAQmx_Val_Polynomial 10449 Scale values by using an Nth order polynomial equation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Two-Point Linear

Two-Point Linear First

DAQmx_AI_Bridge_TwoPointLin_First_ElectricalVal

Data Type: float64
Description: Specifies the first electrical value, corresponding to DAQmx_AI_Bridge_TwoPointLin_First_PhysicalVal. Specify this value in the unit indicated by DAQmx_AI_Bridge_ElectricalUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_TwoPointLin_First_PhysicalVal

Data Type: float64
Description: Specifies the first physical value, corresponding to DAQmx_AI_Bridge_TwoPointLin_First_ElectricalVal. Specify this value in the unit indicated by DAQmx_AI_Bridge_PhysicalUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Two-Point Linear Second

DAQmx_AI_Bridge_TwoPointLin_Second_ElectricalVal

Data Type: float64
Description: Specifies the second electrical value, corresponding to DAQmx_AI_Bridge_TwoPointLin_Second_PhysicalVal. Specify this value in the unit indicated by DAQmx_AI_Bridge_ElectricalUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_TwoPointLin_Second_PhysicalVal

Data Type: float64
Description: Specifies the second physical value, corresponding to DAQmx_AI_Bridge_TwoPointLin_Second_ElectricalVal. Specify this value in the unit indicated by DAQmx_AI_Bridge_PhysicalUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Bridge Table

DAQmx_AI_Bridge_Table_ElectricalVals

Data Type: float64*
Description: Specifies the array of electrical values that map to the values in DAQmx_AI_Bridge_Table_PhysicalVals. Specify this value in the unit indicated by DAQmx_AI_Bridge_ElectricalUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_Table_PhysicalVals

Data Type: float64*
Description: Specifies the array of physical values that map to the values in DAQmx_AI_Bridge_Table_ElectricalVals. Specify this value in the unit indicated by DAQmx_AI_Bridge_PhysicalUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Bridge Polynomial

DAQmx_AI_Bridge_Poly_ForwardCoeff

Data Type: float64*
Description: Specifies an array of coefficients for the polynomial that converts electrical values to physical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_Poly_ReverseCoeff

Data Type: float64*
Description: Specifies an array of coefficients for the polynomial that converts physical values to electrical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Charge

DAQmx_AI_Charge_Units

Data Type: int32
Description: Specifies the units to use to return charge measurements from the channel.

Valid values

DAQmx_Val_Coulombs 16102 Coulombs.
DAQmx_Val_PicoCoulombs 16103 PicoCoulombs.
DAQmx_Val_FromCustomScale 10065 Units a custom scale specifies. If you select this value, you must specify a custom scale name.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

TEDS

DAQmx_AI_Is_TEDS

Data Type: bool32
Description: Indicates if the virtual channel was initialized using a TEDS bitstream from the corresponding physical channel.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_TEDS_Units

Data Type: char*
Description: Indicates the units defined by TEDS information associated with the channel.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

Analog Input General Properties

Analog Input Configuration

DAQmx_AI_Coupling

Data Type: int32
Description: Specifies the coupling for the channel.

Valid values

DAQmx_Val_AC 10045 Remove the DC offset from the signal.
DAQmx_Val_DC 10050 Allow NI-DAQmx to measure all of the signal.
DAQmx_Val_GND 10066 Remove the signal from the measurement and measure only ground.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Impedance

Data Type: float64
Description: Specifies the input impedance of the channel.

Valid values

50 50 Ohms.
75 75 Ohms.
1000000 1 M Ohm.
10000000000 10 G Ohm.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_TermCfg

Data Type: int32
Description: Specifies the terminal configuration for the channel.

Valid values

DAQmx_Val_RSE 10083 Referenced Single-Ended.
DAQmx_Val_NRSE 10078 Non-Referenced Single-Ended.
DAQmx_Val_Diff 10106 Differential.
DAQmx_Val_PseudoDiff 12529 Pseudodifferential.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_InputSrc

Data Type: char*
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Signal Conditioning

DAQmx_AI_ResistanceCfg

Data Type: int32
Description: 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.

Valid values

DAQmx_Val_2Wire 2 2-wire mode.
DAQmx_Val_3Wire 3 3-wire mode.
DAQmx_Val_4Wire 4 4-wire mode.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_LeadWireResistance

Data Type: float64
Description: Specifies in ohms the resistance of the wires that lead to the sensor.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Signal Conditioning Bridge

DAQmx_AI_Bridge_Cfg

Data Type: int32
Description: Specifies the type of Wheatstone bridge connected to the channel.

Valid values

DAQmx_Val_FullBridge 10182 Sensor is a full bridge. If you set DAQmx_AI_Excit_UseForScaling to TRUE, NI-DAQmx divides the measurement by the excitation value. Many sensors scale data to native units using scaling of volts per excitation.
DAQmx_Val_HalfBridge 10187 Sensor is a half bridge. If you set DAQmx_AI_Excit_UseForScaling to TRUE, NI-DAQmx divides the measurement by the excitation value. Many sensors scale data to native units using scaling of volts per excitation.
DAQmx_Val_QuarterBridge 10270 Sensor is a quarter bridge. If you set DAQmx_AI_Excit_UseForScaling to TRUE, NI-DAQmx divides the measurement by the excitation value. Many sensors scale data to native units using scaling of volts per excitation.
DAQmx_Val_NoBridge 10228 Sensor is not a Wheatstone bridge.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_NomResistance

Data Type: float64
Description: Specifies in ohms the resistance of the bridge while not under load.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_InitialVoltage

Data Type: float64
Description: 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 DAQmx_AI_Bridge_InitialRatio, NI-DAQmx coerces this property to DAQmx_AI_Bridge_InitialRatio times DAQmx_AI_Excit_ActualVal. This property is set by DAQmx Perform Bridge Offset Nulling Calibration. If you set this property, NI-DAQmx coerces DAQmx_AI_Bridge_InitialRatio to the value of this property divided by DAQmx_AI_Excit_ActualVal. If you set both this property and DAQmx_AI_Bridge_InitialRatio, and their values conflict, NI-DAQmx returns an error. To avoid this error, reset one property to its default value before setting the other.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_InitialRatio

Data Type: float64
Description: 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 DAQmx_AI_Bridge_InitialVoltage, NI-DAQmx coerces this property to DAQmx_AI_Bridge_InitialVoltage divided by DAQmx_AI_Excit_ActualVal. If you set this property, NI-DAQmx coerces DAQmx_AI_Bridge_InitialVoltage to the value of this property times DAQmx_AI_Excit_ActualVal. If you set both this property and DAQmx_AI_Bridge_InitialVoltage, and their values conflict, NI-DAQmx returns an error. To avoid this error, reset one property to its default value before setting the other.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Shunt Cal

DAQmx_AI_Bridge_ShuntCal_Enable

Data Type: bool32
Description: Specifies whether to enable a shunt calibration switch. Use DAQmx_AI_Bridge_ShuntCal_Select to select the switch(es) to enable.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_Select

Data Type: int32
Description: Specifies which shunt calibration switch(es) to enable. Use DAQmx_AI_Bridge_ShuntCal_Enable to enable the switch(es) you specify with this property.

Valid values

DAQmx_Val_A 12513 Switch A.
DAQmx_Val_B 12514 Switch B.
DAQmx_Val_AandB 12515 Switches A and B.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_ShuntCalASrc

Data Type: int32
Description: Specifies whether to use internal or external shunt when Shunt Cal A is selected.

Valid values

DAQmx_Val_BuiltIn 10200 Use the internal shunt.
DAQmx_Val_UserProvided 10167 Use an external shunt.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_GainAdjust

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_ShuntCalAResistance

Data Type: float64
Description: Specifies in ohms the desired value of the internal shunt calibration A resistor.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_ShuntCalAActualResistance

Data Type: float64
Description: Specifies in ohms the actual value of the internal shunt calibration A resistor.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_ShuntCalBResistance

Data Type: float64
Description: Specifies in ohms the desired value of the internal shunt calibration B resistor.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_ShuntCal_ShuntCalBActualResistance

Data Type: float64
Description: Specifies in ohms the actual value of the internal shunt calibration B resistor.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Balance

DAQmx_AI_Bridge_Balance_CoarsePot

Data Type: int32
Description: Specifies by how much to compensate for offset in the signal. This value can be between 0 and 127.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Bridge_Balance_FinePot

Data Type: int32
Description: Specifies by how much to compensate for offset in the signal. This value can be between 0 and 4095.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Current Shunt Resistor

DAQmx_AI_CurrentShunt_Loc

Data Type: int32
Description: Specifies the shunt resistor location for current measurements.

Valid values

DAQmx_Val_Internal 10200 Use the built-in shunt resistor of the device.
DAQmx_Val_External 10167 Use a shunt resistor external to the device. You must specify the value of the shunt resistor by using DAQmx_AI_CurrentShunt_Resistance.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_CurrentShunt_Resistance

Data Type: float64
Description: Specifies in ohms the external shunt resistance for current measurements.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Excitation

DAQmx_AI_Excit_Sense

Data Type: int32
Description: Specifies whether to use local or remote sense to sense excitation.

Valid values

DAQmx_Val_Local 16095 Local.
DAQmx_Val_Remote 16096 Remote.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_Src

Data Type: int32
Description: Specifies the source of excitation.

Valid values

DAQmx_Val_Internal 10200 Use the built-in excitation source of the device. If you select this value, you must specify the amount of excitation.
DAQmx_Val_External 10167 Use an excitation source other than the built-in excitation source of the device. If you select this value, you must specify the amount of excitation.
DAQmx_Val_None 10230 Supply no excitation to the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_Val

Data Type: float64
Description: Specifies the amount of excitation that the sensor requires. If DAQmx_AI_Excit_VoltageOrCurrent is DAQmx_Val_Voltage, this value is in volts. If DAQmx_AI_Excit_VoltageOrCurrent is DAQmx_Val_Current, this value is in amperes.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Excitation Advanced

DAQmx_AI_Excit_UseForScaling

Data Type: bool32
Description: 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 DAQmx_AI_Max and DAQmx_AI_Min to reflect the scaling.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_UseMultiplexed

Data Type: bool32
Description: Specifies if the SCXI-1122 multiplexes the excitation to the upper half of the channels as it advances through the scan list.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_ActualVal

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_DCorAC

Data Type: int32
Description: Specifies if the excitation supply is DC or AC.

Valid values

DAQmx_Val_DC 10050 DC excitation.
DAQmx_Val_AC 10045 AC excitation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_VoltageOrCurrent

Data Type: int32
Description: Specifies if the channel uses current or voltage excitation.

Valid values

DAQmx_Val_Voltage 10322 Voltage excitation.
DAQmx_Val_Current 10134 Current excitation.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Excit_IdleOutputBehavior

Data Type: int32
Description: 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.

Valid values

DAQmx_Val_ZeroVoltsOrAmps 12526 Drive excitation output to zero.
DAQmx_Val_MaintainExistingValue 12528 Continue generating the current value.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

AC Excitation

DAQmx_AI_ACExcit_Freq

Data Type: float64
Description: Specifies the AC excitation frequency in Hertz.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ACExcit_SyncEnable

Data Type: bool32
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ACExcit_WireMode

Data Type: int32
Description: 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.

Valid values

DAQmx_Val_4Wire 4 4-wire.
DAQmx_Val_5Wire 5 5-wire.
DAQmx_Val_6Wire 6 6-wire.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Sensor Power

DAQmx_AI_SensorPower_Voltage

Data Type: float64
Description: Specifies the voltage level for the sensor's power supply.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_SensorPower_Cfg

Data Type: int32
Description: Specifies whether to turn on the sensor's power supply or to leave the configuration unchanged.

Valid values

DAQmx_Val_NoChange 10160 Sensor power supply configuration is not changed.
DAQmx_Val_Enabled 16145 Sensor power supply is turned on.
DAQmx_Val_Disabled 16146 Sensor power supply is turned off.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_SensorPower_Type

Data Type: int32
Description: Specifies the type of power supplied to the sensor.

Valid values

DAQmx_Val_DC 10050 Sensor power supply generates a single DC voltage level.
DAQmx_Val_AC 10045 Sensor power supply generates an AC voltage.
DAQmx_Val_BipolarDC 16147 Sensor power supply generates a pair of DC voltage levels.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Signal Conditioning Thermocouple

DAQmx_AI_OpenThrmcplDetectEnable

Data Type: bool32
Description: 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 DAQmx_Read_OpenThrmcplChansExist to determine if any channels were open.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Thrmcpl_LeadOffsetVoltage

Data Type: float64
Description: Specifies the lead offset nulling voltage to subtract from measurements on a device. This property is ignored if open thermocouple detection is disabled.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Atten

Data Type: float64
Description: Specifies the amount of attenuation to use.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ProbeAtten

Data Type: float64
Description: Specifies the amount of attenuation provided by the probe connected to the channel. Specify this attenuation as a ratio.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Lowpass Filter

Analog Filter

Analog Lowpass

DAQmx_AI_Lowpass_Enable

Data Type: bool32
Description: Specifies whether to enable the lowpass filter of the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Lowpass_CutoffFreq

Data Type: float64
Description: Specifies the frequency in Hertz that corresponds to the -3dB cutoff of the filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Lowpass Advanced

Switched Capacitor

DAQmx_AI_Lowpass_SwitchCap_ClkSrc

Data Type: int32
Description: 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.

Valid values

DAQmx_Val_Internal 10200 Internal to the device.
DAQmx_Val_External 10167 External to the device.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Lowpass_SwitchCap_ExtClkFreq

Data Type: float64
Description: Specifies the frequency of the external clock when you set DAQmx_AI_Lowpass_SwitchCap_ClkSrc to DAQmx_Val_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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Lowpass_SwitchCap_ExtClkDiv

Data Type: uInt32
Description: Specifies the divisor for the external clock when you set DAQmx_AI_Lowpass_SwitchCap_ClkSrc to DAQmx_Val_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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Lowpass_SwitchCap_OutClkDiv

Data Type: uInt32
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Analog Input Digital Filter

DAQmx_AI_DigFltr_Enable

Data Type: bool32
Description: Specifies whether the digital filter is enabled or disabled.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DigFltr_Type

Data Type: int32
Description: Specifies the digital filter type.

Valid values

DAQmx_Val_Lowpass 16071 Lowpass filter.
DAQmx_Val_Highpass 16072 Highpass filter.
DAQmx_Val_Bandpass 16073 Bandpass filter.
DAQmx_Val_Notch 16074 Notch filter.
DAQmx_Val_Custom 10137 Custom filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DigFltr_Response

Data Type: int32
Description: Specifies the digital filter response.

Valid values

DAQmx_Val_ConstantGroupDelay 16075 Constant group delay filter response.
DAQmx_Val_Butterworth 16076 Butterworth filter response.
DAQmx_Val_Elliptical 16077 Elliptical filter response.
DAQmx_Val_HardwareDefined 10191 Use the hardware-defined filter response.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DigFltr_Order

Data Type: uInt32
Description: Specifies the order of the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Digital Lowpass

DAQmx_AI_DigFltr_Lowpass_CutoffFreq

Data Type: float64
Description: Specifies the lowpass cutoff frequency of the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Highpass

DAQmx_AI_DigFltr_Highpass_CutoffFreq

Data Type: float64
Description: Specifies the highpass cutoff frequency of the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Bandpass

DAQmx_AI_DigFltr_Bandpass_CenterFreq

Data Type: float64
Description: Specifies the center frequency of the passband for the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DigFltr_Bandpass_Width

Data Type: float64
Description: Specifies the width of the passband centered around the center frequency for the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Notch

DAQmx_AI_DigFltr_Notch_CenterFreq

Data Type: float64
Description: Specifies the center frequency of the stopband for the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DigFltr_Notch_Width

Data Type: float64
Description: Specifies the width of the stopband centered around the center frequency for the digital filter.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Digital Filter Advanced

DAQmx_AI_DigFltr_Coeff

Data Type: float64*
Description: Specifies the digital filter coefficients.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Filter_Enable

Data Type: bool32
Description: Specifies the corresponding filter enable/disable state.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Filter_Freq

Data Type: float64
Description: Specifies the corresponding filter frequency (cutoff or center) of the filter response.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Filter_Response

Data Type: int32
Description: Specifies the corresponding filter response and defines the shape of the filter response.

Valid values

DAQmx_Val_Comb 16152 Comb filter response.
DAQmx_Val_Bessel 16153 Bessel filter response.
DAQmx_Val_Brickwall 16155 Brickwall filter response.
DAQmx_Val_Butterworth 16076 Butterworth filter response.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Filter_Order

Data Type: uInt32
Description: Specifies the corresponding filter order and defines the slope of the filter response.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_FilterDelay

Data Type: float64
Description: 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 DAQmx_AI_FilterDelayUnits. You can adjust this amount of time using DAQmx_AI_FilterDelayAdjustment.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_FilterDelayUnits

Data Type: int32
Description: Specifies the units of DAQmx_AI_FilterDelay and DAQmx_AI_FilterDelayAdjustment.

Valid values

DAQmx_Val_Seconds 10364 Seconds.
DAQmx_Val_SampleClkPeriods 10286 Sample Clock Periods.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_RemoveFilterDelay

Data Type: bool32
Description: Specifies if filter delay removal is enabled on the device.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_FilterDelayAdjustment

Data Type: float64
Description: Specifies the amount of filter delay that gets removed if DAQmx_AI_RemoveFilterDelay is enabled. This delay adjustment is in addition to the value indicated by DAQmx_AI_FilterDelay. This delay adjustment is in the units you specify with DAQmx_AI_FilterDelayUnits.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_AveragingWinSize

Data Type: uInt32
Description: Specifies the number of samples to average while acquiring data. Increasing the number of samples to average reduces noise in your measurement.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Digitizer/ADC

DAQmx_AI_ResolutionUnits

Data Type: int32
Description: Indicates the units of DAQmx_AI_Resolution.
Restrictions: Not Settable

Valid values

DAQmx_Val_Bits 10109 Bits.

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_Resolution

Data Type: float64
Description: Indicates the resolution of the analog-to-digital converter of the channel. This value is in the units you specify with DAQmx_AI_ResolutionUnits.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_RawSampSize

Data Type: uInt32
Description: Indicates in bits the size of a raw sample from the device.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_RawSampJustification

Data Type: int32
Description: Indicates the justification of a raw sample from the device.
Restrictions: Not Settable

Valid values

DAQmx_Val_RightJustified 10279 Samples occupy the lower bits of the integer.
DAQmx_Val_LeftJustified 10209 Samples occupy the higher bits of the integer.

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_ADCTimingMode

Data Type: int32
Description: 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 DAQmx_AIConv_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.

Valid values

DAQmx_Val_Automatic 16097 Uses the most appropriate supported timing mode based on the Sample Clock Rate.
DAQmx_Val_HighResolution 10195 Increases resolution and noise rejection while decreasing conversion rate.
DAQmx_Val_HighSpeed 14712 Increases conversion rate while decreasing resolution.
DAQmx_Val_Best50HzRejection 14713 Improves 50 Hz noise rejection while decreasing noise rejection at other frequencies.
DAQmx_Val_Best60HzRejection 14714 Improves 60 Hz noise rejection while decreasing noise rejection at other frequencies.
DAQmx_Val_Custom 10137 Use DAQmx_AI_ADCCustomTimingMode to specify a custom value controlling the tradeoff between speed and resolution.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ADCCustomTimingMode

Data Type: uInt32
Description: Specifies the timing mode of the ADC when DAQmx_AI_ADCTimingMode is DAQmx_Val_Custom.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Dither

DAQmx_AI_Dither_Enable

Data Type: bool32
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Channel Calibration

DAQmx_AI_ChanCal_HasValidCalInfo

Data Type: bool32
Description: Indicates if the channel has calibration information.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_ChanCal_EnableCal

Data Type: bool32
Description: Specifies whether to enable the channel calibration associated with the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ChanCal_ApplyCalIfExp

Data Type: bool32
Description: Specifies whether to apply the channel calibration to the channel after the expiration date has passed.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Calibration Scaling Parameters

DAQmx_AI_ChanCal_ScaleType

Data Type: int32
Description: Specifies the method or equation form that the calibration scale uses.

Valid values

DAQmx_Val_Polynomial 10449 Scale values by using an Nth order polynomial equation.
DAQmx_Val_Table 10450 Map an array of prescaled values to an array of corresponding scaled values, with all other values scaled proportionally.
DAQmx_Val_None 10230

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Table

DAQmx_AI_ChanCal_Table_PreScaledVals

Data Type: float64*
Description: Specifies the reference values collected when calibrating the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ChanCal_Table_ScaledVals

Data Type: float64*
Description: Specifies the acquired values collected when calibrating the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Polynomial

DAQmx_AI_ChanCal_Poly_ForwardCoeff

Data Type: float64*
Description: Specifies the forward polynomial values used for calibrating the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ChanCal_Poly_ReverseCoeff

Data Type: float64*
Description: Specifies the reverse polynomial values used for calibrating the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ChanCal_OperatorName

Data Type: char*
Description: Specifies the name of the operator who performed the channel calibration.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ChanCal_Desc

Data Type: char*
Description: Specifies the description entered for the calibration of the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Verification

DAQmx_AI_ChanCal_Verif_RefVals

Data Type: float64*
Description: Specifies the reference values collected when verifying the calibration. NI-DAQmx stores these values as a record of calibration accuracy and does not use them in the scaling process.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_ChanCal_Verif_AcqVals

Data Type: float64*
Description: Specifies the acquired values collected when verifying the calibration. NI-DAQmx stores these values as a record of calibration accuracy and does not use them in the scaling process.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

General Advanced

Advanced Range

DAQmx_AI_Rng_High

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Rng_Low

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DCOffset

Data Type: float64
Description: Specifies the DC value to add to the input range of the device. Use DAQmx_AI_Rng_High and DAQmx_AI_Rng_Low to specify the input range. This offset is in the native units of the device .

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_Gain

Data Type: float64
Description: Specifies a gain factor to apply to the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_SampAndHold_Enable

Data Type: bool32
Description: 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 DAQmx_AI_AutoZeroMode to perform an auto zero on the channel.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

High Accuracy Settings

DAQmx_AI_AutoZeroMode

Data Type: int32
Description: Specifies how often to measure ground. NI-DAQmx subtracts the measured ground voltage from every sample.

Valid values

DAQmx_Val_None 10230 Do not perform an autozero.
DAQmx_Val_Once 10244 Perform an auto zero at the beginning of the acquisition. This auto zero task might not run if you have used DAQmx Control Task previously in your task.
DAQmx_Val_EverySample 10164 Perform an auto zero at every sample of the acquisition.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Chop

DAQmx_AI_ChopEnable

Data Type: bool32
Description: Specifies whether the device will chop its inputs. Chopping removes offset voltages and other low frequency errors.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Analog Input Data Transfer And Memory

DAQmx_AI_DataXferMaxRate

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DataXferMech

Data Type: int32
Description: Specifies the data transfer mode for the device.

Valid values

DAQmx_Val_DMA 10054 Direct Memory Access. Data transfers take place independently from the application.
DAQmx_Val_Interrupts 10204 Data transfers take place independently from the application. Using interrupts increases CPU usage because the CPU must service interrupt requests. Typically, you should use interrupts if the device is out of DMA channels.
DAQmx_Val_ProgrammedIO 10264 Data transfers take place when you call an NI-DAQmx Read function or an NI-DAQmx Write function.
DAQmx_Val_USBbulk 12590 Data transfers take place independently from the application using a USB bulk pipe.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DataXferReqCond

Data Type: int32
Description: Specifies under what condition to transfer data from the onboard memory of the device to the buffer.

Valid values

DAQmx_Val_OnBrdMemMoreThanHalfFull 10237 Transfer data from the device when more than half of the onboard memory of the device fills.
DAQmx_Val_OnBrdMemNotEmpty 10241 Transfer data from the device when there is data in the onboard memory.
DAQmx_Val_OnbrdMemCustomThreshold 12577 Transfer data from the device when the number of samples specified with DAQmx_AI_DataXferCustomThreshold are in the device FIFO.
DAQmx_Val_WhenAcqComplete 12546 Transfer data when the acquisition is complete.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_DataXferCustomThreshold

Data Type: uInt32
Description: Specifies the number of samples that must be in the FIFO to transfer data from the device if DAQmx_AI_DataXferReqCond is DAQmx_Val_OnbrdMemCustomThreshold.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_UsbXferReqSize

Data Type: uInt32
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_UsbXferReqCount

Data Type: uInt32
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_MemMapEnable

Data Type: bool32
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Compression

DAQmx_AI_RawDataCompressionType

Data Type: int32
Description: Specifies the type of compression to apply to raw samples returned from the device.

Valid values

DAQmx_Val_None 10230 Do not compress samples.
DAQmx_Val_LosslessPacking 12555 Remove unused bits from samples. No resolution is lost.
DAQmx_Val_LossyLSBRemoval 12556 Remove unused bits from samples. Then, if necessary, remove bits from samples until the samples are the size specified with DAQmx_AI_LossyLSBRemoval_CompressedSampSize. This compression type limits resolution to the specified sample size.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Lossy Lsb Removal

DAQmx_AI_LossyLSBRemoval_CompressedSampSize

Data Type: uInt32
Description: Specifies the number of bits to return in a raw sample when DAQmx_AI_RawDataCompressionType is set to DAQmx_Val_LossyLSBRemoval.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Input Device Scaling Coefficients

DAQmx_AI_DevScalingCoeff

Data Type: float64*
Description: 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 array corresponds to a term of the equation. For example, if index two of the array 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.
Restrictions: Not Settable

You can get this attribute using:   DAQmxGetChanAttribute

DAQmx_AI_EnhancedAliasRejectionEnable

Data Type: bool32
Description: Specifies whether to enable enhanced alias rejection. Leave this property set to the default value for most applications.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_OpenChanDetectEnable

Data Type: bool32
Description: Specifies whether to enable open channel detection.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Input Limits Fault Detection

DAQmx_AI_InputLimitsFaultDetect_UpperLimit

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_InputLimitsFaultDetect_LowerLimit

Data Type: float64
Description: 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.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

DAQmx_AI_InputLimitsFaultDetectEnable

Data Type: bool32
Description: Specifies whether to enable input limits fault detection.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Power Supply Fault Detection

DAQmx_AI_PowerSupplyFaultDetectEnable

Data Type: bool32
Description: Specifies whether to enable power supply fault detection.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

Overcurrent Detection

DAQmx_AI_OvercurrentDetectEnable

Data Type: bool32
Description: Specifies whether to enable overcurrent detection.

You can get/set/reset this attribute using:   DAQmxGetChanAttribute   DAQmxSetChanAttribute   DAQmxResetChanAttribute

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