Sending a CAN frame with DLC > 8 using the .Net API (CanPort.dll)

Hi,

I know it seems a bit odd but I'm trying to send a frame over CAN with the DLC being set to a value greater than 8.

(I still expect the driver to only transmit 8 bytes.)

As stated in your CAN driver documentation (Version 2.06, 2015-03-23), such values will silently be sent (despite actually transmitting only 8 bytes of payload).

Now my problem is that your .NET API implementation does not accept any DLC parameter greater than 8 and does not transmit any frames on invocation. I.e. an errorcode/exception occurs.

Can you think of a workaround that allows me to use your API and still send frames with DLC > 8 ?

Maybe WriteRegister()/WriteRegisterRM() could do the trick ?

I'm using an EFUSA9 w\ WinEC2013.

Thanks & Best Regards

Philipp

Hi,

I got that the maximum transmissible payload is hardlimited to 8 byte. But still, I want to set the DLC to a value greater than 8. Of course, doing so won't extend the MTU, and I don't expect it to do so.

All I'm looking for is to set the DLC to a kind of 'invalid' value of e.g. 10 and transmit only 8 byte of data.

Nevertheless, I currently found that CanPort.Write(string tosend) accepts arbitrary DLC values without error and truly sets the bits on the line like given.

If you know another method which spares the conversion from binary to ascii, please let me know.

Best Regards

Quote from fs-support_ZU

you would like to transmit addional information using the 4th bit of DLC.

Indeed. Since CANopen SDOs always use the entire 8 bytes of payload, the lowest 3 bit of the DLC are wasted in such communication. So I'm trying to use them for some data encoding.