If we want to improve the readability of the displayed data that is read from the CAN bus, it is advisable in some cases to display the name instead of the numeric value. Thus, a text description can be assigned to specific values. A typical example is the CCVS1 (PGN FEF1) message according to the FMS standard and SAE J1939.
This message also contains, for example, information about the clutch and brake pedal. These are two-bit variables whose values are defined as follows:
00 - Pedal released
01 - Pedal depressed
10 - Error
11 - Not available
Here are still the states to remember. 0-pedal released, 1-depressed, 3-unknown value.
However, for the cruise control item (Cruise Control States), where it is already a three-bit variable, it is more complicated because there are more values (possible combinations):
000 - Off/Disabled
001 - Hold 010 - Accelerate
011 - Decelerate
100 - Resume
101 - Set
110 - Accel. Override
111 - Not available
Fortunately, the PP2CAN program and the Data view tool allow you to define a text description for these UNSIGNED values. The descriptions can be edited in the EYE file editor in the window that opens after pressing the Naming button.
A text name is added for each value. It is not necessary to name all the values, but it is possible to name only some of them. The values of the variable that are not named will be displayed only by value. The list of values and their names can be saved to a file as a template and reused for another value.
The result can be seen in the next picture. Both the value and the textual description of the value are displayed, so it is not necessary to search the documentation for the meaning of the value.
This function is available from PP2CAN version 3.047.