CRC checksum calculation

[Tom Eilers]

I have a Marstek Venus3 Home battery that communicates with a Marstek CT003 netpower meter. I intercepted a data package with Wireshark from Venus to CT003.

If I send this captured data package to the CT003 with UDP in Labview I receive a good answer from CT003. No problem so far. But if I want replicate how they calculate the CRC checksum from that package, I don't get the right CRC checksum in Labview. See VI. The last 2 bytes in package are the CRC checksum.

In the VI is the Python code the I found at Github, to see how they calculate the CRC checksum and replicate that in Labview.

Question what am I doing wrong. 

CT003 CRC checksum.vi

[ShaunR]

The CRC is in hex. You are using to Decimal instead of  to Hex

 -> 

[crossrulz]

You should replace the Type Cast with a String To Byte Array. It turns the type cast into a NoOp under the hood and is just a lot easier to read.

I also highly recommend you turn on the Display Style for all of your string controls and indicators (Right-Click->Visible Items->Display Style). This is a way of making sure you know how your data is encoded and eliminate a lot of confusion.

CT003 CRC checksum.vi

[Tom Eilers]

Thank you for your very fast answers.

How stupid from me using the wrong conversion.  Also the simplification of String to Byte array.

Good night.