IviACPwrArbWaveform Extension Group
The IviACPwrArbWaveform extension group defines an AC power source capable of producing user-defined arbitrary waveforms. The IviACPwrArbWaveform extension group includes VIs for writing, clearing, and returning information about arbitrary waveform capabilities and catalogs.
An arbitrary waveform is a user-defined series of sequential data points that describe an output waveform for a full cycle (360°). The frequency, phase angle, RMS amplitude and DC offset of the arbitrary waveform at the power source output is defined by the capability group and property shown in the following table.
| Waveform Property | Capability Group | Property |
|---|---|---|
| Frequency | IviACPwrBase | Frequency |
| Phase Angle | IviACPwrPhase | Phase Angle [PHA] |
| RMS Amplitude | IviACPwrBase | Voltage Level |
| DC Offset | IviACPwrDCGeneration | DC offset |
The amplitude of the waveform data array passed to the IviACPwr Write Arbitrary Waveform [ARB] VI is rescaled to the native waveform amplitude range supported by the AC power source. The number of data points in the waveform data array is automatically resampled to the native waveform data points supported by the AC power source.
The IviACPwrArbWaveform extension group includes read-only attributes that define the maximum number of arbitrary waveforms the power source can store, the number of presently stored and available waveforms, and the optimal number of data points of an arbitrary waveform. The VIs include writing and clearing arbitrary waveforms, and querying the arbitrary waveform catalog.
In addition to supporting user-defined arbitrary waveforms, the AC power source contains a base Sine waveform that is always present. Instrument vendors may also define additional fixed waveforms that cannot be cleared.
The driver must not allow user-defined or fixed vendor-defined waveforms to contain a DC offset. This is because the DC offset of the power source output voltage must be exclusively controlled by the IviAcPwrDCGeneration extension capability group. The DC offset can be determining by adding together all data points of the waveform. The absolute value of the sum must be less than 0.001% of the peak-to-peak amplitude.
Waveforms are referenced using a string name. Use this name to clear a waveform from the power source memory (allowing other waveforms to be written) or to specify which waveform the power source should use when generating the voltage on an output phase.
The waveform data values may affect the maximum output voltage the power source can generate using that waveform.
IviACPwrArbWaveform VIs
IviACPwr Clear Arbitrary Waveform [ARB]
IviACPwr Write Arb Waveform [ARB]
IviACPwr Query Arb Waveform Catalog [ARB]
IviACPwrArbWaveform Properties
IviACPwr Num Waveforms Max [ARB]
IviACPwr Num Optimal Data Points [ARB]
IviACPwr Fixed Waveform Count [ARB]
IviACPwr User Waveform Count [ARB]
IviACPwr Available Waveform Count [ARB]