User Manual

Protocol Analysis
R&S
®
Scope Rider RTH
193User Manual 1326.1578.02 ─ 08
8.5.3.2 DBC Files for CAN
Industry-standard DBC files contain more information than PTT and CSV files and
translate the abstract decode results to human language. For each frame, the frame ID
and the symbolic name of the ID are given; the frames are also called messages in
CAN. The data of a CAN message can consist of several "signals". The DBC file pro-
vides the label, unit, start bit, length and other indicators for each signal. For state-
encoded signals, the meaning of the states is given.
In the demo example, the message "EngineData" has the decimal ID 2,166,573,756
and consists of 8 data bytes. These 8 bytes are defined as 6 signals. The first one,
"PetrolLevel", starts at bit #24, has a length of 8 bit, and the unit is liter. The signal
"IdleRunning" is state-encoded. It has only one bit. The binary value 0 means "Run-
ning", and the binary value 1 means "Idle".
Example: CAN DBC file section
BO_ 2166573756 EngineData: 8 Engine
SG_ PetrolLevel : 24|8@1+ (1,0) [0|255] "l" ...
SG_ EngPower : 48|16@1+ (0.01,0) [0|350] "kW" ...
SG_ EngForce : 32|10@1+ (1,0) [0|1000] "N" ...
SG_ IdleRunning : 23|1@1+ (1,0) [0|1] "" ...
SG_ EngTemp : 16|7@1+ (2,-50) [-50|150] "degC" ....
SG_ EngSpeed : 0|13@1+ (1,0) [0|8000] "rpm" ...
....
VAL_ 2166573756 IdleRunning 0 "Running" 1 "Idle" ;
If a DBC file is loaded, the bus menu provides an additional entry: Display Labels.
Figure 8-16: Display of an CAN DBC file
CAN (Option R&S RTH-K3)