Technical data

Using Segmented Memory Acquisition to Capture More Data 12
Agilent InfiniiVision 7000B Series Oscilloscopes Evaluation Guide 65
The oscilloscope should now be capturing random CAN frames (packets
of data) while triggering on Start-of-frame (SOF). Again, to capture more
frames, we could re-scale the timebase. However, the number of
consecutive frames that the oscilloscope could capture using
conventional acquisition memory at a high sample rate would be limited.
Let’s now set up a Segmented Memory acquisition to capture 500
consecutive CAN frames.
13 Press [Acquire].
14 Press Segmented; then, select 500 (# of Segments).
15 Now, press Segmented to begin a segmented memory acquisition.
The oscilloscope should have just captured and decoded 500 consecutive
CAN frames. Let’s now review all of the CAN frames and determine how
long of a time-span the oscilloscope just captured.
16 Press Current Seg.
17 Review all 500 packets of CAN data by rotating the selection knob.
18 Rotate the selection knob until Current Segment 500 is selected on
shown on screen.
Notice that each segment/burst has been time-tagged with a time value
relative to the first captured segment (Segment #1). Segment #500
should have a time-tag of approximately 1 second. Capturing this much
serial data using conventional acquisition memory would be impossible.
Let’s now see how we can examine this serial data in the oscilloscope’s
serial “lister” display mode.