I am attempting to convert a CRC calculator, written in C, to a LabVIEW VI. It looked easy to cut and paste the relevant calculations into a formula node, but I have come unstuck. in C I can do: ushort value = (ushort)(I<<8) The second 'ushort' is there to remove any overflow characters by chopping it back to 8 bits. I tried replacing the ushort with uInt8 but no joy. If I do without the (ushort) LabVIEW recognises the overflow and rounds the byte down to FF, which is not what I want. The LabVIEW logical shift operator does work correctly, but, as the code is more subtle and clever than I am, I don't really want to go down the spaghetti route if I can avoid it. BTW, don't think I hadn't thought to convert the C code to a DLL and import it that way, but I would need outside help with that, plus the complication of supporting the code. Any help much appreciated, Regards, Ian

Found the right combination of settings. So here is a reduced version of my code that will work with your algorithm. It does not use the lookup table, but it is simple and works.

LabVIEW

Bitwise left shift in formula node.

Solved!

Here are my VIs for the CRC-16 using that polynomial. They were saved in LV 2017. If you need an earlier version let me know. They use a table lookup.

What it looks like:

Mark Yedinak
Certified LabVIEW Architect
LabVIEW Champion

"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

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