CAN DBC Edit

Edit DBC files so the result always parses. Never emit a full DBC from the model.

Hard rules

• Do not write BO_, SG_, VAL_, BA_, or CM_ lines from scratch.
• Do not invent hex IDs in BO_ (IDs are decimal; extended IDs use the Vector high-bit encoding).
• Do not hand-compute Motorola start bits or bit packing. Use the library.
• Do not ship a file that fails scripts/validate_dbc.py --strict.
• Preserve everything not requested — IDs, start bit, length, byte order, signedness, multiplex M/mN, nodes, senders/receivers, attributes, comments, value tables, signal groups, encoding, CRLF, signal order.

Choose a path

Path A — surgical (default). Isolated field change on an existing line — factor, offset, min/max, unit, comment, VAL_ label, cycle-time attribute.

1. python3 scripts/validate_dbc.py --strict <file.dbc>
2. Locate the exact line (grep / read). Change only those characters.
3. Validate again. If parse fails, revert. Do not "fix" a broken dump by rewriting the file.