286 6000 Series Oscilloscope User’s Guide
6 Displaying Data
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.
Type s o f F ram es
•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.
Example: If a data frame contains an active error flag, both the
FRAMES counter and the ERR counter will be incremented. If a
data frame contains an error that is not an active error it is
considered a partial frame and no counters are incremented.