LeCroy DDA 7 Zi series, Operator'S Manual

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WavePro 7Zi
145
WP700Zi-OM-E-RevA
To increase vertical resolution: In the example at left, the lower ("inner")
trace has been significantly enhanced by a three-bit enhanced resolution
function.
To reduce noise: The example at left shows enhanced resolution of a
noisy signal. The original trace (left top) has been processed by a 2-bit
enhanced resolution filter. The result (left bottom) shows a "smooth" trace,
where most of the noise has been eliminated.
Note: Enhanced resolution can only improve the resolution of a trace; it cannot improve the accuracy or linearity
of the original quantization. The pass-band will cause signal attenuation for signals near the cut-off frequency.
The highest frequencies passed may be slightly attenuated. Perform the filtering on finite record lengths. Data
will be lost at the start and end of the waveform: the trace will be slightly shorter after filtering. The number of
samples lost is exactly equal to the length of the impulse response of the filter used: between 2 and 117
samples. Normally this loss (just 0.2 % of a 50,000 point trace) is not noticed. However, you might filter a record
so short there would be no data output. In that case, however, the instrument would not allow you to use the
ERES feature.
Setting Up Enhanced Resolution (ERES)
1. Touch Math Math Setup on the menu bar.
2. Touch a function tab F1 through Fx [The number of math traces available depends on the software options
loaded on your scope. See Specifications.]
3. Touch inside the Operator1 data entry field.
4. Select ERES from the All Functions or Filter group of Math functions.
5. Touch the Trace On checkbox.