Teledyne LeCroy USB Protocol Suite User Manual (Voyager_Advisor T3_Mercury) - Manual (Page 268)

Teledyne LeCroy Corporation General Recording Options
268 USB Protocol Suite User Manual
transmissions between the host and device, or by adding filters to the analyzer recording to
reduce the quantity of data per second that the analyzer is capturing and uploading to the
Analyzer host machine.
Note: In both Spooled Recording and Conventional Single Buffer Recording, when large captures are
made, the application automatically segments large traces into 512‐MB segments. The spooled
captures are stored in the USB Protocol Suite directory and are numbered using the analyzer
serial number and a 0 to N numeric sequence.
10.2.5 Buffer Size
You can adjust the size of the recording buffer from a very small size up to the maximum
available in your product.
The Trigger Mode option determines how this buffer is used. Although the Analyzer has a
large physical memory, the efficiency of the recording is about a 2:1 ratio of physical
memory to actual USB traffic. Shorter USB packets yield a slightly less efficient recording.
The non‐traffic portion of physical memory is utilized for control and timing information.
Note: The scale is not linear and affords more granularity in the smaller buffer sizes.
Note: To make the full buffer available for recording, you can select to Disable Generator Memory in
the Misc.USB 2.0 tab of the Recording Options dialog.
10.2.6 Trigger Position
You can adjust the amount of recording to be done post‐trigger or select where you want
the Trigger located within the defined buffer. You can adjust the Triggering Position
between 1 and 99% post‐trigger. Trigger Position is available only when Manual Trigger
or Event Trigger is selected as trigger mode.
As an example, if the buffer size is set to 16 MB, then for the following Trigger Position
settings, the amount of pre‐trigger and post‐trigger data is:
 95% post‐triggering: 0.8 MB pre‐trigger, 15.2 MB post‐trigger
 75% post‐triggering: 4 MB pre‐trigger, 12 MB post‐trigger
 50% post‐triggering: 8 MB pre‐trigger, 8 MB post‐trigger
 25% post‐triggering: 12 MB pre‐trigger, 4 MB post‐trigger
 5% post‐triggering: 15.2 MB pre‐trigger, 0.8 MB post‐trigger
Note: When a Trigger occurs, recording continues until the post‐trigger amount of the buffer is filled or
when Stop is selected.
10.2.7 Options Name
The Options Name is a descriptive label of the current Recording Options settings.
Options Names are associated with files that have a .rec suffix.