2-28
IM 701450-51E
Bit Rate
Select a data transfer rate for the CAN Bus data to be analyzed from the following.
10, 20, 33.333, 50, 62.5, 83.333, 95.238, 100, 125, 250, 500, or 1000 [kbps]
You can also enter an arbitrary value from the keyboard that appears on screen.
Selectable range: 10.000 to 1000.000 [kbps]
Resolution:
Bit time (reciprocal of the bit rate) resolution of 0.5
µ
s
Sample Point
Select a percentage for judging the bus level (recessive/dominant).
18.8, 21.9, 25.0, 28.1, 31.3, 34.4, 37.5, 40.6, 43.8, 46.9, 50.0, 53.1, 56.3, 59.4, 62.5,
65.6, 68.8, 71.9, 75.0, 78.1, 81.3, 84.4, 87.5, or 90.6 [%]
The point at which the input CAN Bus signal waveform changes from recessive to
dominant is taken as 0%, and the point one bit time (the reciprocal of the specified bit
rate) thereafter is taken as 100%, thereby allowing expression of the sample point as a
percentage.
Vdiff
You can select a connection method for the differential probe from below. In either case,
the logical value is: recessive = 1 and dominant = 0.
CAN_L–CAN_H
The recessive voltage level is greater than the dominant voltage level.
CAN_H–CAN_L
The dominant voltage level is greater than the recessive voltage level.
Note
•
For the further information on connecting the differential probe, see section 2.3,
“Connecting the Probe.”
•
The bit rate setting is connected with the setting in the CAN Setup dialog box (see page 2-
5), and the CURSOR menu (see page 2-35).
•
The Vdiff setting is connected with the setting in the CAN Setup dialog box (see page 2-5).
Threshold Level (Thr Upper/Thr Lower)
To analyze the indefinite data on the signal, specify two signal levels, Thr Upper and Thr
Lower. By comparing the measured data against the threshold levels, 0, 1, or indefinite
data is determined. The data is determined as follows according to the Vdiff setting.
• When Vdiff = CAN_L–CAN_H
When measured data < Thr Lower:
0
When measured data > Thr Upper:
1
When Thr Lower
≤
measured data
≤
Thr Upper: Indefinite data
• When Vdiff = CAN_H–CAN_L
When measured data < Thr Lower:
1
When measured data > Thr Upper:
0
When Thr Lower
≤
measured data
≤
Thr Upper: Indefinite data
Bits determined to be indefinite data are considered to have the same value as the
previous bit, and the results are displayed. Also, frames in the analysis results list and
the detailed analysis list containing indefinite data appear with an asterisk (*).
2.5 Analyzing/Searching Data