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.

1 Over­view

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

2.1.1 Signals

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 information.

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 the dis­play (deci­mal or hexadecimal)
• a unit
• sca­ling and offset
• ran­ge

Also, enu­me­ra­ti­ons are pos­si­ble, that’s descrip­ti­ons of values (see 2.1.3 also).

2.1.2 Mul­ti­ple­xer

Mul­ti­ple­xers 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 transferred.

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 pla­ced within the data field free­ly. Mul­ti­ple­xers also can have value descrip­ti­ons (see 2.1.3)

2.1.3 Enu­me­ra­ti­ons

Enu­me­ra­ti­ons, that descrip­ti­ons of values are making are pos­si­ble to con­nect values of signals or mul­ti­ple­xers to a string. While decoded, the­se strings are dis­play­ed. For ins­tance, you can dis­play “On” and “Off” to show the sta­te of a switch.

2.1.4 Mes­sa­ges

Mes­sa­ges repre­sent a CAN mes­sa­ge with a cer­tain ID and can con­tain a mul­ti­ple­xer and seve­ral 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.

2.1.5 Watch­list

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

1. Open a new file.
   Click File and New.
2. Crea­te signals and enumerations
   Click on the but­ton  to add a signal and open its edit win­dow. Give it a meaningful name and edit it.
   To use a value descrip­ti­on switch value “dis­play” to “value descrip­ti­on” and click . Now add your description.
3. Crea­te messages
   Click the 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.
4. Crea­te watchlists
   Use com­ple­te mes­sa­ges or signals only for your watchlists.
5. Edit file description
   The descrip­ti­on is used in CAN­vi­si­on, CAN­touch and CBT2 to choo­se a cer­tain sym­bol file.