Importing CAN message issue

[benmtech]

I am using a C125 in a non motorsport application and have an issue importing the attached .dbc file. When the import process is complete, there are some exclamation marks by some channels which indicate “DBC file cannot be converted. Only integer value types supported”. It would appear that these channels are all 32bit length channels. I had another .dbc file with 2 channels of 48bit and this crashed the Dash Manager but I thought 32 bit was OK. Any suggestions greatfully received! And Happy Christmas everyone!

[NathanB]

Hi Ben,

Dash manager only accept messages with a byte length of up to 4 (so 32 bit), so the 48 bit messages will not be possible to be imported.

The non integer channels you have in that DBC are IEEE floating point arithmetic. what this means is that the 32 bits comprise of a maths equation, not an integer (a number)

There are several types of IEEE floating point arithmetic that can be used, which interpret these values differently, and as a result have a different output number.

The most suitable person to answer this question will be back in the office tomorrow, so I will query him as to whether or not it is possible at all to bring in IEEE equations (to my knowledge we don't support it)

[benmtech]

Thanks Nathan. I was aware of the 48 bit issue and removed these messages from the .dbc file. I will wait with interest for an answer fro your collegue. Thanks

[benmtech]

Thanks Nathan. I was aware of the 48 bit issue and removed these messages from the .dbc file. I will wait with interest for an answer from your collegue. Thanks

[adrian]

I did a couple of tests with 48bit channels and couldn't get Dash Manager to crash. Are you able to send me the original dbc file that made DM crash? Although 48bits is not supported DM should handle it correctly and give you a warning the channel hasn't been added.

Unfortunately our Dashes don't support receiving IEEE Floating Point numbers over CAN. If you were only logging the data I think it would be possible to log the channel and then convert it to the correct value in i2 but the Dash wouldn't be able to Display the actual channel value.

[benmtech]

The DBC file is attached. FYI I am using DM 6.40.30. I have just tried it again with the same crashed result. I am not worried about the 48 bit messages as they are repeats of latitude and longditude.

Is there any appitite at MoTeC to alter your firmware to accept IEEE floating point messages as it is live data display that I am interested in. All the data is logged elsewhere. Thanks for your support.

[adrian]

The reason it is crashing is because "Position_Longitude" has a negative factor. I'll put a bug report in for that. The 48 bit channels aren't assigned to a message so they aren't causing any issues.

I'll put in a feature request to read floats directly off CAN, however I don't think it will be likely that it will be added anytime soon, if at all. It isn't a very common way to transmit channels on CAN.

[benmtech]

Thank you for helping get to the bottom of the problem. I would have liked to have sold this product alongside my VBOX sales as a very configurable display. The Racelogic product is not yet developed sufficiently well in this area and I am pretty sure that they will not feel the need to get to the level that you have with Display Creator. Its been an interesting experiment and thanks again for your input.