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Printout (described below) is due in class on Tuesday, February 4, 2003
Create a Virtual Instrument that will be used to generate an arbitrary
waveform from user specified information. Your subVI should have the
following controls and indicators. Default values are given in
brackets when appropriate.
Controls
- Waveform Type - Used to select the
type of waveform (sine wave, triangular wave, sawtooth wave, square
wave). Use an enumerated data type. [Sine Wave]
- Amplitude - The peak amplitude of
the waveform. Use a double-precision floating point value. [1.00]
- Frequency (Hz) - The frequency in
Hz (i.e. cycles/sec) of the waveform. Use a double-precision floating
point value. [10.0]
- DC Offset - A constant offset of
the waveform from zero. Use a double-precision floating point value.
[0.0]
- Sampling Info - A cluster
containing:
- Sampling Rate (Fs =
samples/sec) - This
is the number of samples (points) per second in the waveform. Use a double-precision
floating point value. [1000]
- Number of Samples (#s) - The total
number of samples (points) in the waveform. Use an long integer (I32)
[1000]
- Duty Cycle - The percent of time a
square wave remains high over one complete period. This control
will be used for square
waves only. Use a double-precision floating point value. [50 %]
- Error In - The standard Error In
cluster.
Indicators
- Waveform Out - The waveform
described by the parameters Waveform Type, Amplitude, Frequency, DC
Offset, Sampling Rate, Number of Samples, and Duty Cycle. Display
this waveform on a waveform graph on the front panel. Use a waveform
data type.
- Error Out - The standard Error Out
Cluster.
 You will need to use the waveform generation
VIs named Sine Waveform.vi, Triangle Waveform.vi, Sawtooth Waveform.vi, and Square
Waveform.vi.
Refer to the help files for additional information about
these VIs. You will probably notice that there is a "waveform
function generator VI" in the same palette as these VIs. Your
waveform generator will be MUCH simpler because I am not asking you to keep
track of the phase of the signal. In fact, you should hard wire a TRUE
Boolean constant to the Reset Phase? input and a 0.0 to the Phase Input of
the Waveform subVIs.
If Error In contains an error
then your VI should do nothing except return the error. Use standard
Error I/O from the waveform subVIs to pass appropriate values to the Error
Out cluster of your VI.
You will later use this subVI to
generate a waveform of a selected frequency that is exactly one cycle long.
 
Additional Requirements
-
Document the controls and indicators on
this virtual instrument.
-
Create an icon for your subVI and connect the
controls and indicators to terminals on the icon so it can be called by
a top-level VI in a later exercise.
-
Document the subVI by entering a
description in the VI Properties dialog box.
-
Print your subVI with the "Complete
Documentation" option of the print dialog and hand the printout in
during class.
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