CRC32

[jamiva]

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@453443474 wrote:

Thanks for your reply. There are plenty of method of CRC32. How did you identify which method to be used to achieve the expected CRC32 value(29 FB 89 83)?

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For me it was all trial and error.

I got lucky and found it quickly. You mentioned that the polynomial was probably 0x04C11DB7. So, I started there and methodically changed the other parameters (initial value, final XOR, reverse data, reverse CRC) until I found the right CRC. Initial Value is most often all Zeros (0x00000000) or all 1's (0xFFFFFFFF). Same with the Final XOR. The Reverse Data and Reverse CRC are Booleans and each can be toggled true/false.

NOTE: Your CRC algorithm is slightly different. The standardized CRC-32/ISO-HDLC calculates the CRC value as 83 89 FB 29, but is was simple to reverse the bytes to get your result 29 FB 89 83

[leonardoramal]

Hi, 

I am having the same problem, I am trying to use the examples in the link below, but I am not getting the same answer as I could find in the webpage Online CRC-8 CRC-16 CRC-32 Calculator (crccalc.com): 
https://forums.ni.com/t5/Example-Programs/Calculating-the-CRC32-of-a-File-with-LabVIEW/ta-p/3496230

Example: HEX 000100010400000000

From ccralc.com:

Algorithm	Result	Check	Poly	Init	RefIn	RefOut	XorOut
CRC-32	0x147F6155	0xCBF43926	0x04C11DB7	0xFFFFFFFF	true	true	0xFFFFFFFF

From the Labview example:

I kindly ask for help with this issue

[tst]

If I open the NI verified example in your link, remove the file reading code and use a string instead, I get exactly the value you say you expect:

Note that I set the display style of my string to hex before I pasted your value. This means that the hex value of the bytes in my string are 00, 01, 00, etc.

If you still can't get it to work, you should include your actual code with default values configured, what you expect to see and what you actually see.

[leonardoramal]

It worked, Thank you very much.