Editing Checksum (section)

===Sum complement===

A variant of the previous algorithm is to add all the "words" as unsigned binary numbers, discarding any overflow bits, and append the [[two's complement]] of the total as the checksum.  To validate a message, the receiver adds all the words in the same manner, including the checksum; if the result is not a word full of zeros, an error must have occurred.  This variant, too, detects any single-bit error, but the pro modular sum is used in [[SAE J1708]].<ref>{{cite web|url=http://www.kvaser.com/zh/about-can/related-protocols-and-standards/50.html |title=SAE J1708 |publisher=Kvaser.com |archive-url=https://web.archive.org/web/20131211152639/http://www.kvaser.com/zh/about-can/related-protocols-and-standards/50.html |archive-date=11 December 2013 }}</ref>