Default value for unset signals or unused bits in the frame should be '1' for J1939

[linzbdav]

The default value for unset signals or unused bits in the frame is currently set to '0' but the document SAE J1939-71 in Table 1 defines if a signal is not available or nor requested the value should be 0xFF. Therefore the unset signals ans unused bits should be set to '1'.

[ebroecker]

hi @linzbdav

I was just looking to this issue...

Not sure how to fix this compatible, because I think default value should be 0 for normal can and seems it should be 1 (0xff) for j1939.

What use case you came along with this bug (converting, creation, what ever)?
I just want to know this to find a useful workaround ...

[linzbdav]

Hi @ebroecker
Sorry for my late response I was very busy during the last days. I use the library for creation of CAN-frames, I use a dbc file with all message definition and want to generate the frame with, some messages don't use all bits or I don't want to set a signal then the resulting value in the message should be filled with ones.

[ebroecker]

Hi @linzbdav

do you use canmatrix to create the frame? With encode?