8 data bytes maximum for CAN messages received - why??

[Eimear]

Hi,

Can anyone answer this:

Why is there an 8 byte maximum on the number of data bytes in a CAN message that is received in LabVIEW?

Thanks,
Eimear

[smercurio_fc]

If I read the CAN spec correctly, it says the number of data bytes is limited to 8 bytes.

[MikeS81]

Hi Eimear,

smercurio is right. The CAN bus has only 8 data bytes per message.

Mike

Message Edited by MikeS81 on 04-18-2008 05:21 PM

[Eimear]

Hi,

Thanks for the replies.  I read that in LabVIEW help, but was wondering if anyone knew why this was?

Thanks,
Eimear

[smercurio_fc]

Because it's in the CAN spec, as has already been pointed out. Are you asking why the spec limits to 8 bytes? That question may be better directed at the writers of the spec. What difference does it make?

[Eimear]

It matters because one of CAN messages I can receive on Vector's CANalyzer has 14 bytes of information in the data field, and I want to receive this through NI USB-8473s in LabVIEW.  Does anyone know if this is a NI limitation in some way?

Thanks,
Eimear