AnalogWaveformSample examples for VB

[jpgdpd]

I would like to write an application for acquiring multiple waveforms using VB 2005 (VB 😎 with the Measurement Studios VS2005 assemlies.  Analog sampling has not been an issue, but I would like the timestamping that appears to be part of the AnalogWaveformSample.  I cannot find any examples on how to effectiviley configure channels / timing / tasks for use with this class and the help files do not more than state what it is, not how to use it.  I would appreciate any insite on acquiring waveforms using VB.  Thank you.

[Ecleamus]

Hi John,

Are you already using the AnalogWaveform<TData> class in your application? If so, then you can access the timestamp through the Timing property.  If you are not using this class, then a good starting point is the shipping example GlobalContinuousAI (located in the <MeasurementStudioVS2005>\DotNET\Examples\DAQmxWithUI\GlobalContinuousAI folder) which uses this class along with the AnalogMultiChannelRead class.  In this example, adding a statement like: data(0).Timing.TimeStamp would allow you to get/set the timestamp for the first channel of data.  Note that the return type of the EndReadWaveform method is AnalogWaveform<TData> which means the timing information is set based off the execution of the AI task. Otherwise, the timing property is set to Empty when creating an analog waveform using a constructor.

As far as the AnalogWaveformSample<TData> class goes, you can look at it just as a sample of the AnalogWaveform<TData> class (as it states in the help) which is why there is an Owner property of AnalogWaveform<TData> type.  Thus, the timestamp will be set if the Owner's Timing property is not Empty. Otherwise, no timestamp will be available.  Let me know if this helps.

Have a great day,

Ecleamus Ricks, Jr.
National Instruments
Applications Engineer