While we are on the topic...

K

Kai M. Becker

Am Donnerstag, 1. November 2001 18:33 schrieb Aditya Ayachit:
> 1. Why does ASCII has LRC and RTU has CRC, why not use LRC or CRC for
> both ?

IMHO, ASCII is for easy implementation, while RTU is the more reliable "working horse". Implementing the RTU CRC e.g. in 8051 assembler is tricky. I'm not sure that I would understand my own implementation from 1991.

See http://www.modicon.com/TECHPUBS/intr7.html and
http://www.modicon.com/openmbus/standards/openmbus.htm for the original specs, or ask Modicon, they invented it.

Kai

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C

Curt Wuollet

Perhaps because lrc is simple and crc works with values from 128-255.

Regards

cww

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