Tektronix RSA6100A Series, Help Manual

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General Signal Viewing > DPX Spectrum DPX Spectrum Overview
DPX Spectrum Overview
The DPX Spectrum display enables you to see how traces change over time and thus displays signal events
that cannot be seen on a swept spectrum analyzer. A DPX Spectrum indicates how traces change in two
ways. First, it uses color shading to show how consistent the shape of a trace is. Second, it uses persistence
to hold signals on the screen so you can see them longer.
DPX Spectrum Display
The DPX Spectrum display works by using a two-dimensional array to represent points on the display.
Each time a trace writes to a point on the display, a counter in the array is incremented. A color is assigned
to each point in the display based on the value of its counter. Thus, as acquisitions occur over time, a
colored waveform, the Bitmap, develops on the display that shows how frequently a display point has
been written to.
An important feature of the DPX Spectrum display is persistence. Persistence sets how long a point on
the display will be visible. You can set the Display Persistence to be Variable or In
fi nite. In variable
persistence mode, you specify a decay period that limits how long a point will be displayed. In in fi nite
persistence mode, once a point in the display has been written to, it will remain visible inde fi nitely.
To display the DPX Spectrum view:
1. Select Freq and use the front panel knob or number keys to set the measurement frequency.
2. Select the Displays button or Setup > Displays . This displays the Select Displays dialog box.
3. From the Folders box, select General Signal Viewing .
4. Select DPX Spectrum from the Available displays box.
5. Click the Add button. This will add the DPX Spectrum icon to the Selected Displays box (and remove
it from the Available displays box).
6. Click the OK button. This displays the DPX Spectrum view.
RSA6100A Series Real-Time Spectrum Analyzers Help
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