DigitalCaptureWaveforms.Fetch Method
- Updated2023-11-24
- 2 minute(s) read
DigitalCaptureWaveformsFetch Method
Fetches a defined number of samples for a specified list of sites.
Namespace: NationalInstruments.ModularInstruments.NIDigital
Assembly: NationalInstruments.ModularInstruments.NIDigital.Fx40 (in NationalInstruments.ModularInstruments.NIDigital.Fx40.dll) Version: 2021
Syntax
public uint[][] Fetch( string siteList, string waveformName, int samplesToRead, TimeSpan maxTime, ref uint[][] data )
Public Function Fetch ( siteList As String, waveformName As String, samplesToRead As Integer, maxTime As TimeSpan, ByRef data As UInteger()() ) As UInteger()()
Parameters
- siteList
- Type: SystemString
The comma-delimited list of sites on which to burst the pattern (for example, "site0,site1"). Sites that are not on this list are disabled. All sites are enabled for pattern bursting if the string is empty. - waveformName
- Type: SystemString
The name of the waveform to fetch. Use the waveformName with the capture_start opcode in your pattern. - samplesToRead
- Type: SystemInt32
The number of samples to fetch. Use -1 to fetch all samples after the pattern is finished bursting. - maxTime
- Type: SystemTimeSpan
The maximum amount of time allowed for this method to complete in seconds. An exception is thrown if the method does not complete within this time span. - data
- Type: SystemUInt32
The samples fetched from the capture waveform data for specified sites. The size of this array can be less than or equal to the number of sites specified in the siteList parameter, depending on whether sites are disabled.
Return Value
Type: UInt32The captured data for each site specified. If a site is disabled, not enabled for burst, or the current instrument does not include any capture pins, the method does not return data for that site. Use SortSiteResultsBySite(NIDigital, String, SiteResultType, UInt32, Int32) to order and combine the data to match the siteList. You can also use GetSiteResultsSiteNumbers(String, SiteResultType) to obtain a sorted list of returned sites.
Exceptions
Exception | Condition |
---|---|
IviCDriverException | The NI-Digital Pattern Driver returned an error. |
SelectorNameException | The value for siteList contains an invalid site. |
ArgumentException | The waveform name specified by waveformName does not exist. |
InvalidOperationException | Fetch(String, String, Int32, TimeSpan, UInt32) is called before bursting a pattern. |
Remarks
In order to get best performance, consider fetching fewer samples multiple times rather than fetching large samples at once. This method only returns data from sites that are enabled when fetch is called.