Teledyne LeCroy HDO 4000 Operators Manual - Manual (Page 53)

HDO4000 High Definition Oscilloscope
XY Displays
XY displays plot the phase shift between otherwise identical signals. They can be used to display either
voltage or frequency on both axes, each axis now corresponding to a different signal input, rather than a
different parameter. The shape of the resulting pattern reveals information about phase difference and
frequency ratio.
The sources must have the same X-axis scale.
1. Set up the desired source traces.
2. Go to Display > Display Setup and choose:
l
XY to display only the XY plot.
l
XYSingle to display the XY plot next to a single grid containing both source traces.
3. Touch Input X and Input Y and select your sources from the pop-up menu.
NOTE: The inputs can be any combination of channels, math functions, or memories.
Persistence Overview
The Persistence feature displays waveforms in a manner that helps reveal idiosyncrasies or anomalies in
a repetitive signal. Use Persistence to accumulate on-screen points from many acquisitions to see your
signal change over time. The instrument persistence modes show the most frequent signal path in three-
dimensional intensities of the same color, or graded in a spectrum of colors.
You can show persistence for up to eight inputs for any channel, math function, or memory location (M1
to M4).
Persistence Mode
The Persistence display is generated by repeated sampling of the amplitudes of events over time, and the
accumulation of the sampled data into display maps. These maps create an analog-style display.
Statistical integrity is preserved because the duration (decay) is proportional to the persistence
population for each amplitude or time combination in the data.
A NALOG M ODE
When you select Analog mode, each trace is assigned a different color.
As a persistence data map develops, different intensities of that color are assigned to the range between
a minimum and a maximum population. The maximum population automatically gets the highest
intensity, the minimum population gets the lowest intensity, and intermediate populations get intensities
in between these extremes.
The information in the lower populations (for example, down at the noise level) could be of greater
interest to you than the rest. The Analog persistence view highlights the distribution of data so that you
can examine it in detail.
C OLOR M ODE
Color mode persistence works on the same principle as Analog persistence, but instead uses the entire
color spectrum to map signal intensity: violet for minimum population, red for maximum population. In
this mode, all traces use all colors, which is helpful for comparing amplitudes by seeking like colors
among the traces.
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