How does CRC 16 with lookup table work?

[reynolja]

I have been try to get CRC16 with a lookup table to work but it does not match the CRC for a device I am trying to simulate.  I have attached the code any help would be great.

[0utlaw]

Hello reynolja,

The VI you attached has a missing dependency ("Alternate MIB CRC-16.vi") so it's difficult to tell what may be happening.  There are several CRC examples available on NI.com, I've linked one of the most versatile and recommended ones below - that might be what you're looking for.  If not, I suggest a little more searching- there appear to be at least a dozen other examples in various locations.

Community Example: Inline CRC Reference Library (CRC-32, CRC-16, and CRC-8)

https://decibel.ni.com/content/docs/DOC-11072

Best Regards,

[crossrulz]

You can't just say you need a CRC-16.  There are way too many parameters involved: Polynomial, Initial CRC, Data Inversion.

When it comes to a CRC with a lookup table, it uses precalculated results based on a specific CRC implementation.  If you don't know which implementation it uses, it isn't really usable.

What instrument are you trying to simulate?  What is the exact CRC implementation does it use?

[Wayne.C]

reynolja,

Here is a link to a thread about using a table to generate a CRC.