Hi,

I have a problem encoding data using cantools (Version: 39.4.4).

I'm trying to send an offset encoded on 3 bytes via CAN. It works ok until I reach 65535, but once I go over 16 bits, the two most significant bytes disappear and become 0. However, for example, if I try sending the maximum value for 3 bytes (0xffffff), the value is encoded ok. I've tried using 4 bytes (code below), but I'm still having the same problem. Could anyone please shed some light on this?

Thanks in advance.
Lee

Example code

content = {'cmd': Cmd.LOAD,'offset': offset}
print(content)
foo = db.get_message_by_name('HostToNodeCmd')
data_test = foo.encode(content)
print(''.join('{:02x}'.format(x) for x in data_test))

Offset input values and output values.

Offset = 65535
Output : 02ffff0000000000

Offset = 65535+1
Output : 0200000100000000

offset = 4294967295
Output : 02ffffffff000000

Extract from .dbc file

BO_ 880 HostToNodeCmd: 8 Vector__XXX
    SG_ cmd M : 0|8@1+ (1,0) [0|255] "" Vector__XXX
    SG_ pingLow m0 : 8|32@1+ (1,0) [0|4294967295] "" Vector__XXX
    SG_ pingHigh m0 : 40|24@1+ (1,0) [0|16777215] "" Vector__XXX
    SG_ offset m2 : 8|32@1+ (1,0) [0|4294967295] "" Vector__XXX

SG_MUL_VAL_ 880 offset cmd 2-2;