NI DCPOWER Measurement Attributes

Measurement Attributes

• NIDCPOWER_ATTRIBUTE_SENSE
• NIDCPOWER_ATTRIBUTE_AUTO_ZERO
• NIDCPOWER_ATTRIBUTE_APERTURE_TIME_UNITS
• NIDCPOWER_ATTRIBUTE_APERTURE_TIME
• NIDCPOWER_ATTRIBUTE_POWER_LINE_FREQUENCY
• NIDCPOWER_ATTRIBUTE_SAMPLES_TO_AVERAGE
• NIDCPOWER_ATTRIBUTE_MEASURE_RECORD_LENGTH
• NIDCPOWER_ATTRIBUTE_MEASURE_RECORD_LENGTH_IS_FINITE
• NIDCPOWER_ATTRIBUTE_MEASURE_RECORD_DELTA_TIME
• NIDCPOWER_ATTRIBUTE_FETCH_BACKLOG
• NIDCPOWER_ATTRIBUTE_AUTORANGE_MINIMUM_CURRENT_RANGE
• NIDCPOWER_ATTRIBUTE_AUTORANGE_MINIMUM_VOLTAGE_RANGE
• NIDCPOWER_ATTRIBUTE_AUTORANGE_THRESHOLD_MODE
• NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE
• NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_APERTURE_TIME_MODE
• NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_BEHAVIOR
• NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME
• NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME_UNITS
• NIDCPOWER_ATTRIBUTE_MEASURE_WHEN
• NIDCPOWER_ATTRIBUTE_RESET_AVERAGE_BEFORE_MEASUREMENT
• NIDCPOWER_ATTRIBUTE_DC_NOISE_REJECTION
• NIDCPOWER_ATTRIBUTE_MEASURE_BUFFER_SIZE

NIDCPOWER_ATTRIBUTE_SENSE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150013	ViInt32	R/W	Channel	None	niDCPower_ConfigureSense

Description

Selects either local or remote sensing of the output voltage for the specified channel(s).

Refer to the Local and Remote Sense topic in the NI DC Power Supplies and SMUs Help for more information about sensing voltage on supported channels and about devices that support local and/or remote sensing.

Defined Values:

NIDCPOWER_VAL_LOCAL (1008)	Local sensing is selected.
NIDCPOWER_VAL_REMOTE (1009)	Remote sensing is selected.

Default Value: The default value is NIDCPOWER_VAL_LOCAL if the device supports local sense. Otherwise, the default and only supported value is NIDCPOWER_VAL_REMOTE.

Related Topics:

Local and Remote Sense

NIDCPOWER_ATTRIBUTE_AUTO_ZERO

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150055	ViInt32	R/W	Channel	None	niDCPower_ConfigureAutoZero

Description

Specifies the auto-zero method to use on the device.

Refer to the NI PXI-4132 Measurement Configuration and Timing topics for more information about how to configure your measurements.

Defined Values:

NIDCPOWER_VAL_OFF (0)	Disables auto zero.
NIDCPOWER_VAL_ONCE (1024)	Makes zero conversions following the first measurement after initiating the device. The device uses these zero conversions for the preceding measurement and future measurements until the device is reinitiated.
NIDCPOWER_VAL_ON (1)	Makes zero conversions for every measurement

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Auto Zero

NIDCPOWER_ATTRIBUTE_APERTURE_TIME_UNITS

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150059	ViInt32	R/W	Channel	None	niDCPower_ConfigureApertureTime

Description

Specifies the units of the NIDCPOWER_ATTRIBUTE_APERTURE_TIME attribute for the channel configuration.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Refer to the Aperture Time topic in the NI DC Power Supplies and SMUs Help for more information about how to configure your measurements and for information about valid values.

Defined Values:

NIDCPOWER_VAL_SECONDS (1028)	Specifies aperture time in seconds
NIDCPOWER_VAL_POWER_LINE_CYCLES (1029)	Specifies aperture time in power line cycles (PLCs)

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Aperture Time

NIDCPOWER_ATTRIBUTE_APERTURE_TIME

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150058	ViReal64	R/W	Channel	Yes	niDCPower_ConfigureApertureTime

Description

Specifies the measurement aperture time for the channel configuration. Aperture time is specified in the units set by the NIDCPOWER_ATTRIBUTE_APERTURE_TIME_UNITS attribute.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Refer to the Aperture Time topic in the NI DC Power Supplies and SMUs Help for more information about how to configure your measurements and for information about valid values.

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Aperture Time

NIDCPOWER_ATTRIBUTE_POWER_LINE_FREQUENCY

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150020	ViReal64	R/W	Channel	None	niDCPower_ConfigurePowerLineFrequency

Description

Specifies the power line frequency for specified channel(s). NI-DCPower uses this value to select a timebase for setting the NIDCPOWER_ATTRIBUTE_APERTURE_TIME attribute in power line cycles (PLCs).

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Refer to the measurement configuration and timing topics and DC noise rejection topics of supported devices for more information about how to configure your measurements.

Refer to the following topics for more information about how to configure your measurements:

• NI PXIe-4112 Measurement Configuration and Timing
• NI PXIe-4113 Measurement Configuration and Timing
• NI PXI-4132 Measurement Configuration and Timing
• PXIe-4135 DC Noise Rejection
• NI PXIe-4136/4137 DC Noise Rejection
• NI PXIe-4138/4139 DC Noise Rejection
• NI PXIe-4140/4141 DC Noise Rejection
• NI PXIe-4142/4143 DC Noise Rejection
• NI PXIe-4144/4145 DC Noise Rejection

Defined Values:

NIDCPOWER_VAL_50_HERTZ (50.0)	Specifies a power line frequency of 50 Hz.
NIDCPOWER_VAL_60_HERTZ (60.0)	Specifies a power line frequency of 60 Hz

Default Value: NIDCPOWER_VAL_60_HERTZ

Related Topics:

Measurement Noise Rejection

NIDCPOWER_ATTRIBUTE_SAMPLES_TO_AVERAGE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150003	ViInt32	R/W	Channel	None	None

Description

Specifies the number of samples to average when you take a measurement.

Increasing the number of samples to average decreases measurement noise but increases the time required to take a measurement.

Refer to the NI PXI-4110, NI PXI-4130, NI PXI-4132, or NI PXIe-4154 averaging topic for optional property settings to improve immunity to certain noise types.

For information about improving noise immunity for NI-DCPower devices that support DC noise rejection, refer to Measurement Noise Rejection.

Device	Range of Samples to Average
NI PXI-4110 and NI PXI-4130	1 to 511 samples
NI PXI-4132	1 to 127 samples
NI PXIe-4154	1 to 65,535 samples
All other supported instruments	1

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Measurement Noise Rejection

NIDCPOWER_ATTRIBUTE_MEASURE_RECORD_LENGTH

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150063	ViInt32	R/W	Channel	None	None

Description

Specifies how many measurements compose a measure record. When this attribute is set to a value greater than 1, the NIDCPOWER_ATTRIBUTE_MEASURE_WHEN attribute must be set to NIDCPOWER_VAL_AUTOMATICALLY_AFTER_SOURCE_COMPLETE or NIDCPOWER_VAL_ON_MEASURE_TRIGGER.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Valid Values: 1 to 16,777,216

Default Value: 1

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Related Topics:

NIDCPOWER_ATTRIBUTE_MEASURE_RECORD_LENGTH_IS_FINITE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150064	ViBoolean	R/W	Channel	None	None

Description

Specifies whether to take continuous measurements. Call the niDCPower_AbortWithChannels function to stop continuous measurements. When this attribute is set to VI_FALSE and the NIDCPOWER_ATTRIBUTE_SOURCE_MODE attribute is set to NIDCPOWER_VAL_SINGLE_POINT, the NIDCPOWER_ATTRIBUTE_MEASURE_WHEN attribute must be set to NIDCPOWER_VAL_AUTOMATICALLY_AFTER_SOURCE_COMPLETE or NIDCPOWER_VAL_ON_MEASURE_TRIGGER. When this attribute is set to VI_FALSE and the NIDCPOWER_ATTRIBUTE_SOURCE_MODE attribute is set to NIDCPOWER_VAL_SEQUENCE, the NIDCPOWER_ATTRIBUTE_MEASURE_WHEN attribute must be set to NIDCPOWER_VAL_ON_MEASURE_TRIGGER.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Defined Values:

VI_FALSE (0)	Allows continuous measurement.
VI_TRUE (1)	Does not allow continuous measurement.

Default Value: VI_TRUE

Related Topics:

NIDCPOWER_ATTRIBUTE_MEASURE_RECORD_DELTA_TIME

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150065	ViReal64	RO	Channel	None	None

Description

Queries the amount of time, in seconds, between the start of two consecutive measurements in a measure record. Only query this attribute after the desired measurement settings are committed.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices

Note  This attribute is not available when Auto Zero is configured to Once because the amount of time between the first two measurements and the rest would differ

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Related Topics:

NIDCPOWER_ATTRIBUTE_FETCH_BACKLOG

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150056	ViInt32	RO	Channel	None	None

Description

Returns the number of measurements acquired that have not been fetched yet.

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Related Topics:

NIDCPOWER_ATTRIBUTE_AUTORANGE_MINIMUM_CURRENT_RANGE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150255	ViReal64	R/W	Channel	None	None

Description

Limiting the lowest range used during autoranging can improve the speed of the autoranging algorithm and minimize frequent and unpredictable range changes for noisy signals. The maximum range used is the range that includes the value specified in the compliance limit attribute, NIDCPOWER_ATTRIBUTE_VOLTAGE_LIMIT_RANGE attribute or NIDCPOWER_ATTRIBUTE_CURRENT_LIMIT_RANGE attribute, depending on the selected NIDCPOWER_ATTRIBUTE_OUTPUT_FUNCTION.

Supported Attributes by Device for information about devices that support this attribute

Default Value:Supported Attributes by Device

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Ranges

NIDCPOWER_ATTRIBUTE_AUTORANGE_MINIMUM_VOLTAGE_RANGE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150256	ViReal64	R/W	Channel	None	None

Description

Limiting the lowest range used during autoranging can improve the speed of the autoranging algorithm and minimize frequent and unpredictable range changes for noisy signals. The maximum range used is the range that includes the value specified in the compliance limit attribute, NIDCPOWER_ATTRIBUTE_VOLTAGE_LIMIT_RANGE attribute or NIDCPOWER_ATTRIBUTE_CURRENT_LIMIT_RANGE attribute, depending on the selected NIDCPOWER_ATTRIBUTE_OUTPUT_FUNCTION.

Supported Attributes by Device for information about devices that support this attribute

Default Value:Supported Attributes by Device

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Ranges

NIDCPOWER_ATTRIBUTE_AUTORANGE_THRESHOLD_MODE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150257	ViInt32	R/W	Channel	None	None

Description

Specifies thresholds used during autoranging to determine when range changing occurs.

Note  This attribute is not supported by all devices. Refer to the Supported Attributes by Device for information about devices that support this attribute Defined Values:

NIDCPOWER_VAL_THRESHOLD_MODE_NORMAL (1112)	Thresholds are selected based on a balance between accuracy and hysteresis.
NIDCPOWER_VAL_THRESHOLD_MODE_FAST_STEP (1113)	Optimized for faster changes in the measured signal. Thresholds are configured to be a smaller percentage of the range.
NIDCPOWER_VAL_THRESHOLD_MODE_HIGH_HYSTERESIS (1114)	Optimized for noisy signals to minimize frequent and unpredictable range changes. Thresholds are configured to be a larger percentage of the range.
NIDCPOWER_VAL_THRESHOLD_MODE_MEDIUM_HYSTERESIS (1115)	Optimized for faster changes in the measured signal. Thresholds are configured to be a smaller percentage of the range.
NIDCPOWER_VAL_THRESHOLD_MODE_HOLD (1116)	Attempt to maintain the active range. Thresholds will favor the active range

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Ranges

NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150244	ViInt32	R/W	Channel	None	None

Description

Specifies whether the hardware automatically selects the best range to measure the signal. Note the highest range the algorithm uses is dependent on the corresponding limit range property. The algorithm the hardware uses can be controlled using the NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_APERTURE_TIME_MODE attribute.

Note  This property is not supported by all devices. Refer to the Supported Attributes by Device for information about devices that support this attribute

Note  Autoranging begins at instrument startup and remains active until the instrument is reconfigured or reset Defined Values:

NIDCPOWER_VAL_OFF (0)	The hardware does not select the range.
NIDCPOWER_VAL_ON (1)	The hardware selects the range based on the compliance range and autorange attributes

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Ranges

NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_APERTURE_TIME_MODE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150246	ViInt32	R/W	Channel	Yes	None

Description

Specifies whether the aperture time used for the measurement autorange algorithm is determined automatically or customized using the NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME attribute.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Defined Values:

NIDCPOWER_VAL_APERTURE_TIME_AUTO (0)	NI-DCPower optimizes the aperture time for the autorange algorithm based on the module range.
NIDCPOWER_VAL_APERTURE_TIME_CUSTOM (1)	The user specifies a minimum aperture time for the algorithm using the NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME attribute and the corresponding NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME_UNITS attribute

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Aperture Time

NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_BEHAVIOR

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150245	ViInt32	R/W	Channel	None	None

Description

Specifies the algorithm the hardware uses for measurement autoranging.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices

Defined Values:

NIDCPOWER_VAL_RANGE_UP_TO_LIMIT_THEN_DOWN (0)	Range up to maximum, then down—Go to limit range then range down as needed until measured value is within thresholds.
NIDCPOWER_VAL_RANGE_UP (1)	Range up—Go up one range when the upper threshold is reached.
NIDCPOWER_VAL_RANGE_UP_AND_DOWN (1)	Range up and down—Go up or down one range when the upper/lower threshold is reached

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Ranges

NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150246	ViReal64	R/W	Channel	Yes	None

Description

Specifies the measurement autorange aperture time used for the measurement autorange algorithm. The aperture time is specified in the units set by the NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME_UNITS attribute. This value will typically be smaller than the aperture time used for measurements.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Aperture Time

NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME_UNITS

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150247	ViInt32	R/W	Channel	None	None

Description

Specifies the units of the NIDCPOWER_ATTRIBUTE_MEASURE_AUTORANGE_MINIMUM_APERTURE_TIME attribute.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Defined Values:

NIDCPOWER_VAL_SECONDS (1028)	Specifies aperture time in seconds.
NIDCPOWER_VAL_POWER_LINE_CYCLES (1029)	Specifies aperture time in power line cycles (PLCs)

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

Aperture Time

NIDCPOWER_ATTRIBUTE_MEASURE_WHEN

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150057	ViInt32	R/W	Channel	None	None

Description

Specifies when the measure unit should acquire measurements. Unless this attribute is configured to NIDCPOWER_VAL_ON_MEASURE_TRIGGER, the NIDCPOWER_ATTRIBUTE_MEASURE_TRIGGER_TYPE attribute is ignored.

Refer to the Acquiring Measurements topic in the NI DC Power Supplies and SMUs Help topic for more information about how to configure your measurements.

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Defined Values:

NIDCPOWER_VAL_AUTOMATICALLY_AFTER_SOURCE_COMPLETE (1025)	Acquires a measurement after each Source Complete event.
NIDCPOWER_VAL_ON_DEMAND (1026)	Acquires a measurement when the niDCPower_Measure function or niDCPower_MeasureMultiple function is called.
NIDCPOWER_VAL_ON_MEASURE_TRIGGER (1027)	Acquires a measurement when a Measure trigger is received

Default Value: If the NIDCPOWER_ATTRIBUTE_SOURCE_MODE attribute is set to NIDCPOWER_VAL_SINGLE_POINT, the default value is NIDCPOWER_VAL_ON_DEMAND. This value supports only the niDCPower_Measure function and niDCPower_MeasureMultiple function. If the NIDCPOWER_ATTRIBUTE_SOURCE_MODE attribute is set to NIDCPOWER_VAL_SEQUENCE, the default value is NIDCPOWER_VAL_AUTOMATICALLY_AFTER_SOURCE_COMPLETE. This value supports only the niDCPower_FetchMultiple function.

Related Topics:

NIDCPOWER_ATTRIBUTE_RESET_AVERAGE_BEFORE_MEASUREMENT

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150006	ViBoolean	R/W	Channel	None	None

Description

Specifies whether the measurement returned from any measurement call starts with a new measurement call (VI_TRUE) or returns a measurement that has already begun or completed(VI_FALSE).

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices When you set the NIDCPOWER_ATTRIBUTE_SAMPLES_TO_AVERAGE attribute in the Running state, the output channel measurements might move out of synchronization. While NI-DCPower automatically synchronizes measurements upon the initialization of a session, you can force a synchronization in the running state before you run the niDCPower_MeasureMultiple function. To force a synchronization in the running state, set this attribute to VI_TRUE, and then run the niDCPower_MeasureMultiple function, specifying all channels in the channel name parameter. You can set the NIDCPOWER_ATTRIBUTE_RESET_AVERAGE_BEFORE_MEASUREMENT attribute to VI_FALSE after the niDCPower_MeasureMultiple function completes.

Defined Values:

VI_FALSE (0)	Do not reset the average before measurement.
VI_TRUE (1)	Reset the average before measurement.

Default Value:

Refer to Supported Attributes by Device for the default value by device.

Related Topics:

NIDCPOWER_ATTRIBUTE_DC_NOISE_REJECTION

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150066	ViInt32	R/W	Channel	None	None

Description

Determines the relative weighting of samples in a measurement.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Refer the DC noise rejection topics of supported devices for more information about noise rejection.

NIDCPOWER_VAL_NORMAL (1044)	Normal DC noise rejection.
NIDCPOWER_VAL_SECOND_ORDER (1043)	Second-order DC noise rejection. Refer to Configuring the Measure Unit for supported devices.

Default Value: NIDCPOWER_VAL_NORMAL

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Related Topics:

Measurement Noise Rejection

NIDCPOWER_ATTRIBUTE_MEASURE_BUFFER_SIZE

Specific Attribute

Numeric Value	Data type	Access	Applies to	Coercion	High-Level Functions
1150077	ViInt32	R/W	Channel	None	None

Description

Specifies the number of samples that the active channel measurement buffer can hold.

The default value is the maximum number of samples that a device is capable of recording in one second.

Note  This attribute is not supported by all devices. Refer to Supported Attributes by Device for information about supported devices Valid Range: For the PXIe-4147, 256 to 18000128. For the PXIe-4162/4163, 256 to 1000192. For all other supported instruments, 1000 to 2147483647.

Default Value: Varies by device. Refer to the Supported Attributes by Device topic in the NI DC Power Supplies and SMUs Help for more information about default values.

Note  To specify a channel name when accessing this attribute, you must first initialize the session using the niDCPower_InitializeWithIndependentChannels function Related Topics: