130
4000 X-Series Oscilloscopes Advanced Training Guide
4
Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs
particular Frame ID, or perhaps a set of 640 consecutive frames, for
troubleshooting and analysis. To complete the rest of this lab your scope must be
licensed with the Segmented Memory option.
27
Push the horizontal position/delay knob to re-position the trigger point back to
center-screen.
28
Set the scope's timebase to
1.30 µs/div
. Do this by tapping the timebase value
on the top of the screen, and tapping it again in the pop up window. You can
use the keypad to enter a custom timebase. Set the scope's offset to ~-1.2 µs
to center the frame on the screen. This is done by adjusting Main Delay in the
same timebase pop up menu.
29
Tap the
Search
key to disable the search feature (button light will turn off).
30
Tap the double-up arrows to the top right of the lister to close the lister menu,
31
Press the
[Acquire]
front panel key.
32
Tap the
Segmented
softkey; double-tap on
# of Segs
and set the value to
500
.
33
Tap the
Segmented
softkey to begin a Segmented Memory acquisition.
34
Tap the
Current Segment
softkey; then turn the Entry knob to review all 500
captured segments.
35
Set the
Current Segment
to
500
and note the time-tag of the last captured
segment.
Segmented Memory optimizes oscilloscope acquisition memory by only capturing
important segments of a waveform based on the trigger condition and timebase
setting. In this example, we have selectively captured approximately 25 ms of total
acquisition time as shown in
. Note that we can also view the decoded
FlexRay data in the "lister" format, and we can also perform Search & Navigation
on the segments. This particular example is limited since there are only four unique
frames in the entire signal to analyze, but the exercise should provide insight on
how segmented memory can be advantageous to debugging FlexRay signals.
