K-BUS CRC SPECIFICATION

K-BUS CRC SPECIFICATION

1. An example for CRC of K-bus

Calculating FCS(CRC) for HDLC frame

up vote0down votefavoriteI have the following frame:

7e 01 00 00 01 00 18 ef 00 00 00 b5 20 c1 05 10 02 71 2e 1a c2 05 10 01 71 00 6e 87 02 00 01 42 71 2e 1a 01 96 27 be 27 54 17 3d b9 93 ac 7e

If I understand correctly, then it is this portion of the frame on which the FCS is calculated:

010000010018ef000000b520c1051002712e1ac205100171006e8702000142712e1a019627be2754173db9

I've tried entering this into a number of online calculators but I cant produce 0x93ac from the above data.

http://www.lammertbies.nl/comm/info/crc-calculation.htmlwith input type hex.

How is 0x93ac arrived at?

Thanks,

Barry

serial-portframechecksumcrcshare

HYPERLINK "http://stackoverflow.com/posts/7983862/edit" \o "" improve this questioneditedNov 3 '14 at 19:24

dsolimano5,60832339askedNov 2 '11 at 16:30

Baz90152684

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1 Answer

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HYPERLINK "http://stackoverflow.com/questions/7983862/calculating-fcscrc-for-hdlc-frame?answertab=oldest" \l "tab-top" \o "Answers in the order they were provided" oldest

HYPERLINK "http://stackoverflow.com/questions/7983862/calculating-fcscrc-for-hdlc-frame?answertab=votes" \l "tab-top" \o "Answers with the highest score first" votesup vote4down voteacceptedfirst of all, CRC value is 0xac93

Use this calculator:http://www.zorc.breitbandkatze.de/crc.html Set CRC order 16

Polynomial 1021

Initial valueffff Final valueffff "reverse data bytes"

"reverse CRC result before Final XOR"

Enter your sequence as:

%01%00%00%01%00%18%ef%00%00%00%b5%20%c1%05%10%02%71%2e%1a%c2%05%10%01%71%00%6e%87%02%00%01%42%71%2e%1a%01%96%27%be%27%54%17%3d%b9`

Press "calculate" and you get 0xAC93

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HYPERLINK "http://stackoverflow.com/posts/8841442/edit" \o "" improve this answereditedJan 12 '12 at 21:11

Peter O.12.3k63546answeredJan 12 '12 at 19:57

Ilya562

2. Result calculate K-bus from Relay with stream : 0100026140 024F(http://www.zorc.breitbandkatze.de/crc.html)

3. IEC870 to Kbus Frame (FT1.2)3.1 IEC870

680303684001004116

STARTLENLENSTARTFCADDDATA1CHECKSUMSTOP

START = 68H, STOP = 16, CHECKSUM = FC+DATA1+DATA23.1 KBUS7E0100026140024F7E

FLAGADD?LEN?FCCRC1CRC2FLAG

CRC: CCITT, X16+X12+X5+1

Set CRC order 16

Polynomial 1021

Initial value ffff

Final value ffff

"reverse data bytes"

"reverse CRC result before Final XOR"IEC FRAME

680707687B0100071404009B16

FCADDADDCHKSTOP

KBUS FRAME

010006617B07140400E743

LEN?FC

Note: K-bus HDLC is serial LSB First

PC

TX: 68 07 07 68 |7B 01 00 07 14 04 00| 9B 16

KBUS

TX: 01 00 06 61 |7B 07 14 04 00| E7 A3

PC RX: 68 0B 0B 68 |08 01 00 38 04 8A 3C 2A 01 5D 68| FB 16IEC len = Kbus Len +1, IECFrame lenth = IEC len + 6IEC FC calculate from : 4 to IECFrame Lenth -2

KBUS RX: 01 00 0A 61 |08 38 04 87 3C 2A 01 5D 68| DD E3

Loi busKitz 68 0B 0B 68 08 01 00 38 04 F1 17 06 00 5D 68 18 16

Arduino 68 0B 0B 68 08 01 00 38 04 EF 2B 0C 00 BA D0 F5 16KitZ 68 0B 0B 68 08 01 00 38 04 F4 0B 06 00 5D 68 0F 16Arduino 68 0B 0B 68 08 01 00 38 04 F1 0B 06 00 5D 68 0C 16

Gia tri nay thay doi ngau nhien

Gia tri Kbus + 3