CAN Symbol Editor Manual
The manual for CAN Symbol Editor is only available in German. So here is a short version with the main content in English to help all our non-German-speakers.
The CAN symbol editor is a program to create and edit symbol files which are used in CAN-Bus Tester 2, CANtouch and CANvision. These symbol files empower them able to interpret CAN messages and decode them into a human readable form (symbolic decoding).
2 Functions and control
2.1 Symbol file structure
Signals are the lowest level in a symbol file. They are used to describe the way, how an information is represented in a CAN message. This is for instance a physical parameter, presenting a value and a unit, but also status informations.
For a basic description you need :
- the name
- the number of bits that the signal is using
More detailed optional values can be :
- the byte order, big endian (Motorola) or little endian (Intel)
- type of value (signed or unsigned, for instance float or double)
- number system of display (decimal or hexadecimal)
- an unit
- scaling and offset
Also enumerations are possible, thats descriptions of values (see 2.1.3 also).
Multiplexer in the data field are used to transfer different data with the same CAN ID. The value sets how the following data bytes are assigned. For instance in CANopen SDO the first 3 bytes define, which parameter of the index is transfered.
In our CAN symbol editor only one multiplexer per message is allowed. It can have a length from 1 to 64 bit and can be free placed within the data field. Multiplexer also can have value descriptions (see 2.1.3)
Enumerations, thats descriptions of values are making is possible to connect values of signals or multiplexers to a string. Whilde decoded, these strings are displayed. For instance you can display “On” and “Off” to show the state of a switch.
Messages represent a CAN message with a certain ID and can contain a multiplexer and different signals. Because only within the message the position of a signal is defined and not within the signal, a signal can be used in different messages at the same time.
Watchlists are used to have related messages together. You can have often used messages in one list.
2.2 User interface
2.3 Generate a symbol file
2.3.1 Import from CAN database (dbc)
The quickest way to generate a symbol file is to import a given Vector CAN dbc file. After importing you can manually edit every signal and message. See below.
2.3.2 Generate manually
- Open a new file.
Click File and New.
- Create signals and enumerations
Click on button to add a signal and open its edit window. Give it a meaningful name and edit it.
To use a value descrition switch value “display” to “value description” and klick . Now add your description.
- Create messages
Click symbol to add a new message. Give a name, type of CAN id and id as well as the length of the data field.
Move signals by using drag and drop into the window. Doubleclick to open the edit window where you can define start bit position. Decide if the signal is a multiplexer or not. If yes that set the multiplexer value.
Tab Layout shows the message and where your signals are.
- Create watchlists
Use complete messages or signals only for your watchlists.
- Edit file description
The description is used in CANvision, CANtouch and CBT2 to choose a certain symbol file.