Teledyne LeCroy FlexRay Trigger, Decode and Physical Layer Test - Manual (Page 26)

Trigger Repeatedly, Save Data to a Hard Drive
You may wish to set up your oscilloscope to capture a short or long memory acquisition for a certain trigger
condition, then save data to a hard drive or memory stick whenever the trigger condition is met. This can be easily
done in most LeCroy oscilloscopes. However, you must realize that there is significant trigger “dead time” when
using this method. To minimize dead time, use the method described under Trigger Repeatedly, Store all Triggers
(Sequence Mode).
1. First, set up your desired serial data (or other) trigger condition.
2. Then, choose File Æ Save Waveform from
the menu bar. A dialog is shown where you
can set Save Waveform conditions.
You can set Save Waveform conditions as
follows:
• OFF - No Auto Saving occurs
• WRAP - Auto Save occurs until the hard
drive is filled, then discards the oldest data
to write the newest data
• FILL - Auto Save occurs until the hard drive
is filled
3. Be sure to choose a Binary file format if
you wish to recall the traces into a LeCroy
oscilloscope for later analysis.
Even though the LeCroy oscilloscope hard drives are very large, it is a good idea to make sure that your trigger
condition is set correctly before beginning your acquisitions.
Note: This method is not guaranteed to capture all of your trigger events, since there is a large amount of “dead time” between triggers as the
acquisition is captured, displayed, and stored to the hard drive before the scope is re-armed for a new trigger. Minimize dead time by using
Sequence Mode.
Trigger Repeatedly, Store all Triggers (Sequence Mode)
LeCroy oscilloscope’s have a powerful capability called Sequence Mode that allows you to store all triggered
events by minimizing the dead time between triggers to < 800 nanoseconds. This is ideal for finding repetitive
causes of problems on your serial data buses or associated signals. (Not available in WaveSurfer Series).
Sequence Mode uses long acquisition memory that is divided into “segments.” As triggered events are acquired,
they are stored in acquisition “segments” to be recalled at a later date. The length of each sequence mode
acquisition segment and the total number of segments allowed is roughly determined by the total acquisition
memory in the oscilloscope. For instance, a WaveRunner Xi with VL memory can acquire 10,000 segments each
a maximum of 625 samples long or 10 segments each a maximum of 1.25 megasamples long, or something in
between. Different acquisition memory lengths have different ranges of segments and segment lengths. You can
define any number of segments from 2 to the maximum for that memory length (reference your oscilloscope’s on-
line Help), and any length of segment (as long as there is sufficient acquisition memory). After acquisition of all
segments is complete, you can recall them one-by-one and view them in decoded format on the oscilloscope
screen.
Acquisition dead time is kept to a minimum because there are no operations performed during the acquisition. All
data for each triggered event is written only into high-speed acquisition memory. Until the entire sequence is
completed, there is no updating of the oscilloscope display, or other operations that cause unnecessary dead
time. This is ideal for situations when you cannot take a chance on losing data.
In the example shown below, we have only acquired Channel 1 (the CAN signal) in sequence mode. We could
also acquire additional analog or other signals as desired or as necessary to do a proper analysis.
1. Touch the Timebase descriptor box to open the
Timebase dialog.
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FlexRay-TDP-OM-E Rev A