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CRC16

Can't work out a CRC match.


 

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Author Message
Will
Guest







May 23, 2014 2:48 pm

Hi
I've been around the block with this one.
Pasting it into the online tool, I don't get a match for it, so I am a little confused.
I looked at using revenge to work it out, but found the syntax confusing. I'm not a CRC guru (far from it), so am struggling to make progress. Any help appricated.
This is the message:
000500000000000000000624230C16050E060000000000000054484520544F574552202D204C594D494E47544F4E2020202020202020202020
The checksum from the device is 07AD.

Thanks
Will
Will
Guest







May 23, 2014 3:47 pm

I also ran it through test CRC and got the following results:
CRC16 = 0x07DF / 2015
CRC16 (Modbus) = 0x5053 / 20563
CRC16 (Sick) = 0xCDFF / 52735
CRC-CCITT (0x0000) = 0x3DFB / 15867
CRC-CCITT (0xffff) = 0x806B / 32875
CRC-CCITT (0x1d0f) = 0xD613 / 54803
CRC-CCITT (Kermit) = 0xC2A2 / 49826
CRC-DNP = 0x2CA7 / 11431
CRC32 = 0x476F8D5A / 1198493018
"" :
CRC16 = 0x07DF / 2015
CRC16 (Modbus) = 0x5053 / 20563
CRC16 (Sick) = 0xCDFF / 52735
CRC-CCITT (0x0000) = 0x3DFB / 15867
CRC-CCITT (0xffff) = 0x806B / 32875
CRC-CCITT (0x1d0f) = 0xD613 / 54803
CRC-CCITT (Kermit) = 0xC2A2 / 49826
CRC-DNP = 0x2CA7 / 11431
CRC32 = 0x476F8D5A / 1198493018


None of which matches my CRC.
Gammatester
Guest







May 26, 2014 12:24 pm

I can give you hundreds of algorithms which will produce the given CRC for your test message. To say it another way: if you do not have more test cases or more information about the algorithm there is no way to get definite answer, other than that the algorithm is none of the usual suspects.

Here parameter sets for the polynomial $1021
Code:
===== Result parameter sets =====
CRC=$ad07  Poly=$1021  init=$182d  xorout=$ffff  refin=true   refout=false
CRC=$07ad  Poly=$1021  init=$1a9b  xorout=$0000  refin=false  refout=true
CRC=$07ad  Poly=$1021  init=$1cd0  xorout=$ffff  refin=false  refout=true
CRC=$ad07  Poly=$1021  init=$1e66  xorout=$0000  refin=true   refout=false
CRC=$ad07  Poly=$1021  init=$4174  xorout=$0000  refin=true   refout=true
CRC=$07ad  Poly=$1021  init=$43c2  xorout=$0000  refin=false  refout=false
CRC=$07ad  Poly=$1021  init=$4589  xorout=$ffff  refin=false  refout=false
CRC=$ad07  Poly=$1021  init=$473f  xorout=$ffff  refin=true   refout=true
CRC=$ad07  Poly=$1021  init=$b1e4  xorout=$ffff  refin=false  refout=false
CRC=$07ad  Poly=$1021  init=$b352  xorout=$0000  refin=true   refout=true
CRC=$07ad  Poly=$1021  init=$b519  xorout=$ffff  refin=true   refout=true
CRC=$ad07  Poly=$1021  init=$b7af  xorout=$0000  refin=false  refout=false
CRC=$ad07  Poly=$1021  init=$e8bd  xorout=$0000  refin=false  refout=true
CRC=$07ad  Poly=$1021  init=$ea0b  xorout=$0000  refin=true   refout=false
CRC=$07ad  Poly=$1021  init=$ec40  xorout=$ffff  refin=true   refout=false
CRC=$ad07  Poly=$1021  init=$eef6  xorout=$ffff  refin=false  refout=true
===== done =====

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