ScopeChannelDdc Class
- Updated2023-09-06
- 4 minute(s) read
ScopeChannelDdc Class
Defines the properties related to the digital down converter (DDC) block in a high speed digitizer.
Inheritance Hierarchy
SystemObject
NationalInstruments.ModularInstruments.NIScopeScopeSubObject
NationalInstruments.ModularInstruments.NIScopeScopeChannelDdc
NationalInstruments.ModularInstruments.NIScopeScopeSubObject
NationalInstruments.ModularInstruments.NIScopeScopeChannelDdc
Namespace: NationalInstruments.ModularInstruments.NIScope
Assembly: NationalInstruments.ModularInstruments.NIScope.Fx45 (in NationalInstruments.ModularInstruments.NIScope.Fx45.dll) Version: 2023
Syntax
public sealed class ScopeChannelDdc : ScopeSubObject
Public NotInheritable Class ScopeChannelDdc Inherits ScopeSubObject
The ScopeChannelDdc type exposes the following members.
Properties
| Name | Description | |
|---|---|---|
 | CenterFrequency |
Gets or sets the frequency, in hetrz, at which the DDC block frequency translates the input data. This frequency is the region of the spectrum that you want to downconvert to baseband.
|
| Enabled |
Gets or sets whether the digital down converter (DDC) block of the digitizer is enabled.
|
| FrequencyTranslationEnabled |
Gets or sets whether the frequency translation of the data around the selected center frequency down to baseband is enabled.
|
| FrequencyTranslationPhaseI |
Gets or sets the I oscillator phase in degrees at the first point acquired.
|
| FrequencyTranslationPhaseQ |
Gets or sets the Q oscillator phase in degrees at the first point acquired.
|
| QSource |
Gets or sets the channel that is the input to the Q data stream of the digital downconverter (DDC).
|
Methods
| Name | Description | |
|---|---|---|
 | Equals | Determines whether the specified object is equal to the current object. (Inherited from Object.) |
| GetHashCode | Serves as the default hash function. (Inherited from Object.) |
| GetType | Gets the Type of the current instance. (Inherited from Object.) |
| ToString | Returns a string that represents the current object. (Inherited from Object.) |
Remarks
You can only query or set the properties of this class when the scope session is associated with an instrument that supports onboard signal processing (OSP).
You can use the DDC block of the NI 5142 for the following applications:
-
Alias-Protected Decimation: For alias-protected decimation applications, complete the following steps:
- Set DDC Enabled to .
- Set DdcDataProcessingMode to Real.
- Set SampleRateMin to the desired decimated sample rate.
- Set FrequencyTranslationEnabled to .
-
AM Demodulation: For AM demodulation applications, complete the following steps:
- Set DDC Enabled to .
- Set DdcDataProcessingMode to Real.
- Set SampleRateMin to the desired baseband sample rate.
- Set FrequencyTranslationEnabled to .
- Set CenterFrequency to the carrier frequency of the AM signal you want to downconvert.
-
Quadrature Downconversion: For quadrature downconversion applications, complete the following steps:
- Set DDC Enabled to .
- Set DdcDataProcessingMode to Complex.
- Set SampleRateMin to the desired IQ data rate.
- Set FrequencyTranslationEnabled to .
- Set CenterFrequency to the desired center frequency of the IF band you want to downconvert.
-
Baseband Decimation: For baseband decimation applications, complete the following steps:
- Set DDC Enabled to .
- Set DdcDataProcessingMode to Complex.
- Set SampleRateMin to the desired baseband sample rate.
- Set FrequencyTranslationEnabled to .
- Set QSource to channel "1."
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.