MT Display 3DEye VI

LabView Digital Modulation

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MT Display 3DEye VI

Divides an input complex-valued waveform into segments and displays those segments as overlapping plots on a 3D graph. The VI determines the segment length based on the symbol rate and eye length parameters.

Details

MT Display 3DEye

waveform specifies the modulated data for plotting as a 3D eye diagram.

	t0 specifies the trigger (start) time of the Y array. The default is 0.0.
	dt specifies the time interval between data points in the Y array. The default is 1.0.
	Y specifies the complex-valued signal-only baseband modulated waveform. The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively.

symbol rate specifies the symbol rate of the modulated data, in hertz. The default is 1.0.

eye length specifies the number of symbol periods on the horizontal (X) scale of the 3D eye diagram. The default is 1.

color specifies the 24-bit color in which to plot the segments. If color > white (white = 2²⁴ – 1), then each segment is plotted in a different random color. The default is GREEN 255.

optional settings specifies optional settings that control the plot update rate and enable programmatic interruption. This parameter can be safely left unwired.

segment timing specifies the time to pause between updates of the individual segments as they are plotted. This value can be increased to slow down plot speed or to normalize plot speed because of PC performance differences. If you specify a value for the occurrence refnum for abort parameter, this segment timing value should be sufficiently long to allow the occurrence to be detected. The default is 100 ms.

occurrence refnum for abort specifies whether the VI monitors the occurrence while updating the segments of a plot. If a valid occurrence is wired as an input, this VI monitors the occurrence and exit without completing any remaining plots if the occurrence is fired during the update. You can use this parameter to make the 3D graph utility responsive to user input. When this parameter is unwired, the VI completes a requested graph update without interruption. The default is not a valid occurrence.

clear graph specifies whether to clear the 3D plot before plotting new data. Set this parameter to TRUE to clear the plot. The default is FALSE.

3D curve specifies a reference to the ActiveX 3D graph that displays the plot. This connection is prewired when you select the VI from the front panel controls palette.

autoscale specifies whether to apply autoscaling to the graph referenced in the eye diagram reference control. When this control is set to TRUE, the X axis is scaled to display exactly (eye length × symbol period) seconds, while the Y and Z axes are scaled equally and symmetrically about zero for the largest magnitude of the signal.

The default is FALSE (no autoscaling).

display size specifies the number of segments plotted simultaneously on the 3D graph. If this value is less than the number of available segments in the waveform, the VI plots the additional segments by adding them one at a time to the existing plot. As new segments are added the oldest segments are removed. The default is 100.

Note Because plotting on a 3D graph can be computationally intensive, you can set this parameter to a value that is less than the total number of segments that are available in the input waveform. Doing so limits the maximum number of segments displayed at one time.

error in (no error) can accept error information wired from previously called VIs. Use this information to decide if any functionality should be bypassed in the event of errors from other VIs. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.
	code identifies the error or warning code. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.
	source describes the origin of the error or warning. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

error out passes error or warning information out of a VI to be used by other VIs. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.
	code is the error or warning code. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.
	source describes the origin of the error or warning. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

Details

Tip For a "clean" eye diagram with distinct, nonshifting transitions, the input waveform should have an integer-valued symbol-rate-to-sample-rate ratio.

This VI works in conjunction with a standard LabVIEW graph indicator and is available both from the front panel Controls palette (Controls»Modulation»Digital) and from the block diagram Functions palette (Functions»Modulation»Digital»Utilities).

When selected from the front panel Controls palette, this VI is automatically prewired to the appropriate graph. When this VI is placed from the Functions palette onto the block diagram, no connections are automatically wired and you must manually connect the graph indicator on the block diagram.

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