NI SCOPE Onboard Signal Processing Attributes
- NISCOPE_ATTRIBUTE_DDC_ENABLED
- NISCOPE_ATTRIBUTE_DDC_DATA_PROCESSING_MODE
- NISCOPE_ATTRIBUTE_DDC_FREQUENCY_TRANSLATION_ENABLED
- NISCOPE_ATTRIBUTE_DDC_CENTER_FREQUENCY
- NISCOPE_ATTRIBUTE_FETCH_INTERLEAVED_IQ_DATA
- NISCOPE_ATTRIBUTE_DDC_Q_SOURCE
- NISCOPE_ATTRIBUTE_DDC_FREQUENCY_TRANSLATION_PHASE_I
- NISCOPE_ATTRIBUTE_DDC_FREQUENCY_TRANSLATION_PHASE_Q
- NISCOPE_ATTRIBUTE_EQUALIZATION_FILTER_ENABLED
- NISCOPE_ATTRIBUTE_EQUALIZATION_NUM_COEFFICIENTS
- NISCOPE_ATTRIBUTE_FRACTIONAL_RESAMPLE_ENABLED
- NISCOPE_ATTRIBUTE_OVERFLOW_ERROR_REPORTING
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | None |
Enables/disables the DDC block of the digitizer. When the DDC block is disabled, all DDC-related properties are disabled and have no effect on the acquired signal.
 |
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 |
|---|---|
| Default Value: VI_FALSE |
VI_TRUE
VI_FALSE
| Tip To achieve maximum flatness in the filter response of the device in DDC mode, set the maximum input frequency to full bandwidth (–1). However, keep in mind that this action does not protect against aliasing frequency content of the input signal above (0.5 × Sample Clock Timebase Rate). When using internal clocking, the Sample Clock Timbase Rate is 100 MS/s. |
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DDC Enabled Overview
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViInt32 | R/W | N/A | None | None |
The way in which data is processed by the DDC block.
|
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. |
|---|---|
| Default Value: Complex |
NISCOPE_VAL_REAL—The waveform data points are real numbers (I data)
NISCOPE_VAL_COMPLEX—The waveform data points are complex numbers (IQ data)
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | None |
Enables/disables frequency translating the data around the user-selected center frequency down to baseband.
|
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. |
|---|---|
| Default Value: VI_TRUE |
VI_TRUE
VI_FALSE
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | None |
The frequency at which the DDC block frequency translates the input data.
|
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: Hz |
Default Value: 10 MHz
0 – (0.5 × Sample Clock Timebase Rate for digitizer)
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | N/A | None | None |
Specifies whether a fetch call retrieves a single waveform with I and Q interleaved, or two separate waveforms. If set to TRUE, the number of elements returned by scalar fetch types (such as 16-bit integer) is twice the requested number of samples. If set to FALSE during DDC acquisitions in Complex mode, two noninterleaved arrays of data are returned per channel, per record.
|
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. |
|---|---|
| Default Value: VI_TRUE |
VI_TRUE—A scalar fetch returns an array of waveforms in the following format: IQIQIQ...
VI_FALSE—A scalar fetch returns an array of waveforms in the following format: III...QQQ...
- Frequency Domain Fundamentals
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViString | R/W | Channel | None | None |
Specifies the channel that is the input to the Q data stream of the DDC.
|
Note For multi-instrument sessions, the channel you define with this attribute as the Q data stream and the channel for the corresponding I data stream must both be located within the same physical instrument. |
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|
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. |
|---|---|
| Valid Values: All valid channels for the device |
Default Value: The channel to which the attribute is registered
| Data type | Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | None |
The I oscillator phase in degrees at the first point acquired.
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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: Degrees |
Default Value: 0
–360 to 360
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViReal64 | R/W | Channel | None | None |
The Q oscillator phase in degrees at the first point acquired. Use this attribute only when NISCOPE_ATTRIBUTE_DDC_DATA_PROCESSING_MODE is set to Complex.
|
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: Degrees |
Default Value: 90
–360 to 360
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | Channel | None | None |
Enables the onboard signal processing equalization FIR block, which is connected directly to the input signal. The equalization filter is designed to compensate the input signal for artifacts introduced to the signal outside of the digitizer. Because this filter is a generic FIR filter, any coefficients are valid. Coefficient values should be between +1 and –1.
|
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. |
|---|---|
| Default value: VI_FALSE |
VI_TRUE
VI_FALSE
- Frequency Domain Fundamentals
- Flatness
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViInt32 | RO | Channel | None | None |
Returns the number of coefficients that the equalization FIR filter can accept. This filter is designed to compensate the input signal for artifacts introduced to the signal outside of the digitizer. Because this filter is a generic FIR filter, any coefficients are valid. Coefficient values should be between +1 and –1.
|
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. |
|---|
- Frequency Domain Fundamentals
- Flatness
| Datatype | Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViBoolean | R/W | N/A | None | None |
Enables the onboard signal processing block that resamples the input waveform to the desired sample rate.
| Default Value: | VI_FALSE |
|---|---|
| Valid Values: | VI_TRUE or VI_FALSE |
- Frequency Domain Fundamentals
| Data type |
Access | Applies to | Coercion | High Level Functions |
|---|---|---|---|---|
| ViInt32 | R/W | N/A | None | None |
Configures error reporting when the onboard signal processing block detects an overflow in any of its stages. Overflows lead to clipping of the waveform.
|
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. |
|---|---|
| Default Value: Warning |
NISCOPE_VAL_ERROR_REPORTING_ERROR (0)—NI-SCOPE returns an error when an overflow has occurred in the OSP block.
NISCOPE_VAL_ERROR_REPORTING_WARNING (1)—NI-SCOPE returns a warning when an overflow has occurred in the OSP block.
NISCOPE_VAL_ERROR_REPORTING_DISABLED (2)—NI-SCOPE does not return an error when an overflow has occurred in the OSP block.