NI SCOPE Vertical Attributes
- NISCOPE_ATTRIBUTE_CHANNEL_ENABLED
- NISCOPE_ATTRIBUTE_VERTICAL_RANGE
- NISCOPE_ATTRIBUTE_VERTICAL_OFFSET
- NISCOPE_ATTRIBUTE_MAX_INPUT_FREQUENCY
- NISCOPE_ATTRIBUTE_VERTICAL_COUPLING
- NISCOPE_ATTRIBUTE_INPUT_IMPEDANCE
- NISCOPE_ATTRIBUTE_PROBE_ATTENUATION
- NISCOPE_ATTRIBUTE_CHANNEL_TERMINAL_CONFIGURATION
- NISCOPE_ATTRIBUTE_DIGITAL_GAIN
- NISCOPE_ATTRIBUTE_DIGITAL_OFFSET
- NISCOPE_ATTRIBUTE_BANDPASS_FILTER_ENABLED
- NISCOPE_ATTRIBUTE_DITHER_ENABLED
- NISCOPE_ATTRIBUTE_FLEX_FIR_ANTIALIAS_FILTER_TYPE
- NISCOPE_ATTRIBUTE_HIGH_PASS_FILTER_FREQUENCY
- NISCOPE_ATTRIBUTE_INTERLEAVING_OFFSET_CORRECTION_ENABLED
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | niScope_ConfigureVertical |
Specifies whether the digitizer acquires a waveform for the channel.
VI_TRUE (1)—Acquire data on this channel.
VI_FALSE (0)— Do not acquire data on this channel.
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | Yes | niScope_ConfigureVertical |
Specifies the absolute value of the input range for a channel in volts. For example, to acquire a sine wave that spans between –5 and +5 V, set this attribute to 10.0 V.
Refer to the NI High-Speed Digitizers Help for a list of supported vertical ranges for each device. If the specified range is not supported by a device, the value is coerced up to the next valid range.
- Coercions of Vertical Parameters
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | niScope_ConfigureVertical |
Specifies the location of the center of the range with respect to ground in volts. For example, to acquire a sine wave that spans between 0.0 and 10.0 V, set this attribute to 5.0 V.
 |
Note This attribute is not supported by all digitizers. Refer to the Features Supported by Device for a list of vertical offsets supported for each device. |
|---|
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | niScope_ConfigureChanCharacteristics |
Specifies the bandwidth of the channel. Express this value as the frequency at which the input circuitry attenuates the input signal by 3 dB. The units are hertz.
Refer to the NI High-Speed Digitizers Help for a list of bandwidths supported for each device.
NISCOPE_VAL_BANDWIDTH_FULL (–1.0)
NISCOPE_VAL_BANDWIDTH_DEVICE_DEFAULT (0.0)
NISCOPE_VAL_20MHZ_BANDWIDTH (20000000.0)
NISCOPE_VAL_100MHZ_BANDWIDTH (100000000.0)
NISCOPE_VAL_20MHZ_MAX_INPUT_FREQUENCY (20000000.0)
NISCOPE_VAL_100MHZ_MAX_INPUT_FREQUENCY (100000000.0)
- Bandwidth
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViInt32 | R/W | Channel | None | niScope_ConfigureVertical |
Specifies how the digitizer couples the input signal for the channel. When input coupling changes, the input stage takes a finite amount of time to settle.
NISCOPE_VAL_AC (0)
NISCOPE_VAL_DC (1)
NISCOPE_VAL_GND (2)
- Input Coupling
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | niScope_ConfigureChanCharacteristics |
Specifies the input impedance for the channel in Ohms.
NISCOPE_VAL_50_OHMS (50)
NISCOPE_VAL_1_MEG_OHM (1000000)
- Impedance and Impedance Matching
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | niScope_ConfigureVertical |
Specifies the probe attenuation for the input channel. For example, for a 10:1 probe, set this attribute to 10.0.
Valid Values: Any positive real number. Typical values are 1, 10, and 100.
- Probes and Their Effects
| Datatype | Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViInt32 | R/W | Channel | None | N/A |
Specifies the terminal configuration for the channel.
NISCOPE_VAL_SINGLE_ENDED (0)
NISCOPE_VAL_UNBALANCED_DIFFERENTIAL (1)
NISCOPE_VAL_DIFFERENTIAL (2)
- NI 5922 Channel Terminal Configuration
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | None |
Applies gain to the specified channel in hardware before any onboard signal processing occurs. The output of the digital gain/offset block is as follows:
(ADC value × digital gain) + digital offset
|
Note This attribute can be used only with high-speed digitizers that support onboard signal processing (OSP). NI-SCOPE returns an error if you use this attribute with a device that does not support OSP. |
|---|---|
| Units: Unitless |
Default Value: 1
–1.5 to 1.5
- NI 5622 Onboard Signal Processing (OSP)
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | None |
Applies offset to the specified channel in hardware before any onboard signal processing occurs. The output of the digital gain/offset block is as follows:
(ADC value × digital gain) + digital offset
|
Note This attribute can be used only with high-speed digitizers that support onboard signal processing (OSP). NI-SCOPE returns an error if you use this attribute with a device that does not support OSP. |
|---|---|
| Units: Volts |
Default Value: 0
±(Vertical Range × 0.4)
- NI 5622 Onboard Signal Processing (OSP)
| Datatype | Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | None |
Enables the bandpass filter on the specified channel. For the NI PXIe-5622, set the value to TRUE to enable the IF filtered path 50MHz bandpass filter centered at 187MHz.
| Default Value: | VI_FALSE |
|---|---|
| Valid Values: | VI_TRUE or VI_FALSE |
- Bandwidth
| Datatype | Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | None |
Enables or disables the analog dither on the device.
Using dither can improve the spectral performance of the device by reducing the effects of quantization. However, adding dither increases the power level to the ADC, so you may need to either decrease the signal level or increase the vertical range.
| Default Value: | VI_FALSE |
|---|---|
| Valid Values: | VI_TRUE or VI_FALSE |
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViInt32 | R/W | Channel | None | None |
The NI 5922 flexible-resolution digitizer uses an onboard FIR lowpass antialias filter. Use this attribute to select from several types of filters to achieve desired filtering characteristics. For most applications, the default value of this property is recommended. The other available filters are useful for optimizing settling time measurements of step responses.
Default Value: NISCOPE_VAL_48_TAP_STANDARD
|
Note Settling time values refer to the FIR filter only and do not take into account settling time caused by the analog front end. Refer to the NI PXI-5922 Specifications for combined digital and analog settling times. |
|---|
| NISCOPE_VAL_48_TAP_STANDARD (0) |
This filter is optimized for alias protection and frequency-domain flatness. - Alias protection: ranges from 80 dB to 100 dB depending on sample rate - Settling time: within 14 samples from a 50% vertical trigger point - Cutoff frequency: 0.43 × sample rate - Flatness: Ripple ranges from 0.005 dB to 0.120 dB depending of selected sample rate (refer to the NI PXI-5922 Specifications for more information) - Rise time: Approximately 0.75/(sample rate) |
|---|---|
| NISCOPE_VAL_48_TAP_HANNING (1) |
This filter is optimized for the lowest possible bandwidth for a 48 tap filter and maximizes the signal-to-noise ratio (SNR). - Settling time: within 14 samples from a 50% vertical trigger point - Cutoff frequency: 0.030 × sample rate - Flatness: 0 to –3 dB within cutoff frequency - Rise time: 11.6/(sample rate) |
| NISCOPE_VAL_16_TAP_HANNING (2) |
This filter is optimized for the lowest possible bandwidth for a 16 tap filter and maximizes the SNR. - Settling time: 6 samples from a 50% vertical trigger point - Cutoff frequency: 0.08 × sample rate - Flatness: 0 to –3 dB within cutoff frequency - Rise time: 7.7/(sample rate) |
| NISCOPE_VAL_8_TAP_HANNING (3) |
This filter is optimized for the lowest possible bandwidth for an 8 tap filter and maximizes the SNR. - Settling time: 4 samples from a 50% vertical trigger point - Cutoff frequency: 0.15 × sample rate - Flatness: 0 to –3 dB within cutoff frequency - Rise time: 3.9/(sample rate) |
- Aliasing
- FIR Filters
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | None |
Specifies the frequency for the highpass filter. The device uses one of the valid values listed below. If an invalid value is specified, no coercion occurs.
Units: Hz
Default Value: 0
(PXIe-5164)
- 0
- 90
- 450
- Digital Filtering
| Datatype | Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | None |
Enables the interleaving offset correction on the specified channel.
| !Note | Note If disabled, warranted specifications are not guaranteed. |
|---|
| Default Value: | VI_TRUE |
|---|---|
| Valid Values: | VI_TRUE or VI_FALSE |
- Timed Interleaved Sampling