Chapter 2 Can Bus Signal Analysis Function; Overview Of The Can Bus Analysis Function - YOKOGAWA DL7480 User Manual

Chapter 2 CAN Bus Signal Analysis Function
2.1

Overview of the CAN Bus Analysis Function

CAN Bus Signal Analysis Function
Trigger Function <See page 2-5 for the operating procedure>
Analysis Function <See page 2-19 for the operating procedure>
Search Function <See page 2-23 for the operating procedure>
Cursor Function <See page 2-35 for the operating procedure>
IM 701450-51E
CAN stands for Controller Area Network. It is a serial communication protocol
standardized internationally by the ISO (International Organization for Standardization).
In communications that use CAN, analysis of the physical layer of the CAN Bus is
required when troubleshooting problems that occur due to noise caused by surge voltage
and level fluctuations caused by excessive load after connection.
By using this function, data can be analyzed while displaying the signal waveforms on
the CAN Bus as analog waveforms. In addition, synchronized monitoring of the data on
the CAN bus and the analog waveform is possible.
The CAN Bus signal analysis function consists of the following four main functions.
Acquires CAN Bus signals using the defined frames and fields of the CAN Bus as trigger
conditions. Trigger conditions can be set to SOF, Identifier, Data Field, RTR, or Error
Frame. Triggers can be activated using an AND condition, allowing trigger activation on
frames with specific Identifier and Data Fields.
Triggers can also be activated by combining the trigger conditions of the CAN Bus signal
and the parallel pattern of CH2 to CH8 signal (CH2 to CH4 on the DL7440) (combination
trigger).
[Example] For the Standard Format of the Data Frame
Arbitration Field
S R
O Identifier (11 bits) T
F R
S I
S: When Start of Frame is selected for the trigger condition, the Trigger activates here.
I: When Identifier is selected for the trigger condition, the Trigger activates here.
Analyzes CAN Bus signal data acquired using the trigger function, and displays the
Identifier, Data Field, and Acknowledge values for each frame in a list. By selecting any
number of frames from this analysis results list, the CAN Bus signals for those frames
can be automatically displayed. Details of the analysis results such as frame and error
types can be viewed in a detailed analysis results list. The data from the detailed
analysis results list can be saved to any storage medium in ASCII format. Also, stuff bits
within the CAN Bus signals can be detected, and stuff bit waveforms can be displayed as
math waveforms. The frames to be analyzed are data frames, remote frames, and error
frames.
After analysis of the CAN Bus signal data acquired using the trigger function, searches
for data matching data from a specific frame or field, and displays the corresponding
waveforms on screen. Searches can also be performed for error frames and frames with
indefinite data. Also, after the search, the beginning of the specified field within the
frame can be displayed (field jump). Using this function, the desired field within the
frame can be instantly displayed.
Two cursors can be moved per each CAN Bus bit rate (data transfer rate) while
maintaining a bit rate of space between them. When analyzing or searching, CAN Bus
signal fields and frames can be checked while counting the number of bits.
Control
Field Data Field
I
DLC
r
D
(4 bits)
0
E
2
Recessive
Dominant
2-1