IviSpecAn Fetch Y Trace
IviSpecAnBase Capability Group
This VI returns the trace the spectrum analyzer acquires. The trace is from a previously initiated acquisition. Call the IviSpecAn Initiate.vi to start an acquisition. Call the IviSpecAn Acquisition Status.vi to determine when the acquisition is complete. Once the acquisition is complete, call the Fetch Y Trace VI to return the trace.
You may call the IviSpecAn Read Y Trace.vi instead of the IviSpecAn Initiate.vi. The IviSpecAn Read Y Trace.vi starts an acquisition, waits for the acquisition to complete, and returns the trace in one VI call.
Use the IviSpecAn Fetch Y Trace.vi when acquiring multiple traces. Use a different trace name for each IviSpecAn Fetch Y Trace.vi call. You may also call IviSpecAn Fetch Y Trace.vi after calling IviSpecAn Read Y Trace.vi to acquire subsequent traces.
Note:
This VI does not check the instrument status. Typically, you call this VI only in a sequence of calls to other low-level driver VIs. The sequence performs one operation. You use the low-level VIs to optimize one or more aspects of interaction with the instrument. If you want to check the instrument status, call the IviSpecAn Error-Query.vi at the conclusion of the sequence.
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instrument handle The instrument handle that you obtain from the IviSpecAn Initialize or IviSpecAn Initialize With Options VIs. |
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trace name Pass the name of the trace for the desired amplitude array.
This control accepts either a virtual repeated capability name or an instrument-specific trace name. Virtual repeated capability names are aliases for instrument-specific trace strings. The instrument-specific trace strings can differ from one instrument to another. Virtual repeated capability names allow you to use and swap instruments without having to change the trace names in your source code. You specify virtual repeated capability names in MAX. Default Value: "" |
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array length Pass the number of Amplitude array points requested.
Default Value: None |
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error in (no error) The error in cluster can accept error information wired from VIs previously called. Use this information to decide if any functionality should be bypassed in the event of errors from other VIs.
The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. |
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instrument handle out The instrument handle that you obtain from the IviSpecAn Initialize or IviSpecAn Initialize With Options VIs. |
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actual points Indicates the number of points the VI places in the Amplitude array. Use the IviSpecAn Query Trace Size.vi to determine the number of points the spectrum analyzer acquires. |
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amplitude Returns the amplitude waveform that the spectrum analyzer acquires. This data represents the amplitude of the signals of the sweep from the start frequency to the stop frequency (in frequency domain, in time domain the amplitude array is ordered from beginning of sweep to end). The units are determined by the Amplitude Units parameter of the IviSpecAn Configure Level.vi or by the IviSpecAn>>Basic Operation>>Amplitude Units property. Note: The IviSpecAn Query Trace Size.vi returns the number of points the spectrum analyzer acquires. |
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error out The error out cluster passes error or warning information out of a VI to be used by other VIs.
The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. |