Teledyne LeCroy VirtualProbe - Manual (Page 9)

Operator's Manual
NOTE: there is no need to configure a math function to be the difference between two inputs when using
VirtualProbe.
SDAIII-C OMPLETE L IN Q U SE
When using VirtualProbe from within the SDAIII-CompleteLinQ framework, the data source for the active
lane is configured on the SDAIII-CompleteLinQ Signal dialog.
Measurement Filter Section
The measurement filter section of the Setup dialog configures elements that determine the bandwidth
limit of the filter and the maximum gain.
Auto BW Limit checkbox - Check to automatically determine the best setting for BW limit. The algorithm
uses the Max Boost value to determine the BW value to use.
Max Boost field - Select a value for limiting the maximum boost to apply when de-embedding a block. A
vale that is too high can boost noise and lead to undesirable results.
Filter Order field - The filter utilized for handling the measurement bandwidth is generally a high order
filter. It is implemented as a filter that has a magnitude response given by a Butterworth filter of a given
order. The phase response is always linear. The default value is 20, which is a very high order filter, but for
sharper cutoff, higher orders can be used. A filter rolls off at 20 dB/decade (or 6 dB/octave) more for
every increase in filter order.
BW Limit field -Set a value to limit the bandwidth of the filter.
Applying the Setting
After configuring the general circuit and individual blocks, return to either the Setup or VirtualProbe
dialog and touch the Apply button to apply the settings.
Apply button - Touch to build the system description for the circuit and to compile it. When the Xtalk
box is available, touching Apply compiles all setups or lanes together; without, only the selected lane is
compiled. While compiling, the message "Compiling" is displayed in the lower-right corner of the appli-
cation. The result of the compilation is displayed in the adjacent box. Success is indicated as "OK." If the
oscilloscope still needs an input waveform in order to build the filter, you will see a message to that
effect.
Setup Status LED - An LED next to each setup button displays the current status of the setup:
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Red: Error in setup. Check the setup for any inconsistency in the Num Ports, Input Type, or the
block setup for undefined files or touchstone files with incorrect port count.
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Yellow: Apply needed; touch the Apply button when you are finished making changes to the setup
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Green: Compilation successful.
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Dimmed: The output of the setup is unused.
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