Keysight Technologies DSO-X 2002A, User Manual

Page: 307 / 352

CAN/LIN Triggering and Serial Decode
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Keysight InfiniiVision 2000 X-Series Oscilloscopes User's Guide 307
• Aliased bus values (undersampled or indeterminate) are drawn in pink.
• Unknown bus values (undefined or error conditions) are drawn in red with a "?"
label.
• Flagged error frames are drawn in red with an "ERR" label.
CAN Totalizer
The CAN totalizer provides a direct measure of bus quality and efficiency. The CAN
totalizer measures total CAN frames, flagged error frames, overload frames, and
bus utilization.
The totalizer is always running (counting frames and calculating percentages) and
is displayed whenever CAN decode is displayed. The totalizer counts even when
the oscilloscope is stopped (not acquiring data). Pressing the [Run/Stop] key does
not affect the totalizer. When an overflow condition occurs, the counter displays
OVERFLOW . The counters can be reset to zero by pressing the Reset CAN Counters
softkey.
Types of Frames • Active error frames are CAN frames in which a CAN node recognizes an error
condition during a data or remote frame and issues an active error flag.
• A partial frame occurs when the oscilloscope detects any error condition during
a frame that is not followed by an active error flag. Partial frames are not
counted.
Counters • The FRAMES counter gives the total number of completed remote, data,
overload, and active error frames.
• The OVLD counter gives the total number of completed overload frames and
their percentage of the total number of frames.
• The ERR counter gives the total number of completed active error frames and
their percentage of the total number of frames.
• The UTIL (bus load) indicator measures the percentage of time the bus is active.
The calculation is done on 330 ms periods, approximately every 400 ms.