CAN .dbc files

[NickDastardly]

Hi,

More of a CAN question than a specific LabVIEW one:

I have an application where I want to send information over CAN to a separate programme (ATI Vision) when a button is pressed.  The LabVIEW programme I've created is quite large and operates in several different modes, controlled by case structures, where each mode calculates different information.  I would like to add a case structure to my CAN code so that it only sends data for the mode which is in use, because at the moment it sends default data for the modes not in use as well.  If I do this will the programme I'm sending it to get confused because the .dbc configuration file it uses is expecting data for all the modes?  Or will it just see blank data for the modes not in use? 

Thanks in advance,

Nick

[Kurt_NISalesEngineer]

Hi,

Which kind of API are you working with, channel API or Frame API? The Channel API is favored by many because it provides access to the CAN network in simple physical units that are easy to use. Using this API, the NI-CAN software converts the raw data of the CAN messages to or from the physical units of each channel in the channel configuration. can you attach your VI or your configuration file to the discussion forum post for us to appreciate what you are attempting to do? Please note that NI-CAN V2.1.2 does not support mode dependent messages.

CAN frames are typically 8 byte packets where bytes can be for different modes for example voltage, temperature, value staus of valves etc. In mode dependent certain bits in the frame tell what sort of data the rest of the frame will contain like 'header'

Usually, customers are trying to import a .DBC file into MAX and receiving the error, "This file contains mode dependent messages. Mode dependent messages are not supported by NI-CAN 2.0".

NI-CAN 2.2 has support for mode dependent messages.

You can download NI CAN driver from our website @ www.ni.com/downloads > drivers and updates link

I hope this helps!

Kind Regards,
 
Kirtesh Mistry
Applications Engineer
National Instruments UK & Ireland.