Teledyne LeCroy HDO 4000 Operators Manual - Manual (Page 79)

HDO4000 High Definition Oscilloscope
E DGE M ODE
Edge Mode is used for detecting the occurrence of edges. Events that meet the threshold level are
captured and tabulated. When the acquisition is stopped, scan filters can be applied to the edges to find
specific characteristics. Additional settings for Edge Mode are:
l
Slope -- choose Pos, Neg, or Both.
l
Level is -- choose Percent or Absolute.
l
Percent/Absolute Level -- Enter a threshold value as a percentage of Top to Base or voltage level. A
marker displayed over the source trace indicates the level.
N ON - MONOTONIC M ODE
Non-monotonic Mode looks for edges that cross a threshold more than once between high and low levels.
All events that meet the criteria of slope, hysteresis, and level are presented in a table and highlighted in
the source trace. The value displayed in the table is the difference of the max. and min. of the non-
monotonicity. This can be confirmed with cursors. The hysteresis value is used to eliminate noise. A non-
monotonicity is detected only when its amplitude is greater than the hysteresis. Therefore, when setting a
hysteresis level, set a value that is greater than the amplitude of the noise. Additional settings for Non-
monotonic Mode are:
l
Slope -- choose Pos, Neg, or Both.
l
Hysteresis is -- choose Division, Percent, Absolute.
l
Division/Percent/Absolute -- enter the hysterisis level in the units you selected.
l
Levels are -- choose Percent, Absolute, or Pk-Pk%.
l
High Level and Low Level -- Enter the top and bottom thresholds in the units you selected.
R UNT M ODE
Runt Mode looks for pulses that fail to cross a specified threshhold. You can search for positive-going or
negative-going runts, or both. An adjustable hysteresis band is provided to eliminate noise.
In the case of negative-going runt pulses, the value displayed in the table is the difference (delta) of the
high level of the signal and the runt amplitude (i.e., where the runt bottoms out). This can be confirmed by
placing cursors on the runt pulse and reading the delta Y value in the trace labels. In the case of positive-
going runt pulses, the value displayed in the table is the absolute value of the amplitude of the runt pulse.
Additional settings for Runt Mode are:
l
Runt Type -- choose Both, Pos, or Neg.
l
Hysteresis -- enter the hysteresis level as a percentage or voltage.
l
Low Threshold and High Threshold -- enter the levels as a percentage or voltage.
l
Absolute Levels -- check this box if you want to enter levels as absolute voltage instead of per-
centage.
M EASUREMENT M ODE
Measurement Mode is used for applying filters to measurements to find those that meet your defined
criteria, helping to isolate particular events within many samples. Markers appear over the source trace
to indicate the location of measurement, while the table displays values for the selected parameter that
meet the criteria. Additional Settings for Measurement Mode are:
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