Hello fmanzano85,
Good day. Thank you for the question.
The algorithm on how to calculate CRC-16 (also known as CRC-16/IBM) can be found here - https://wiki.teltonika-gps.com/view/Codec#CRC-16
However, we do not have a reverse lookup table as data length/size and data sent is always different, which is why the CRC will also be different. From the server side, what you will need to do is calculate the CRC according to the algorithm and compare it with the device sent CRC, if they match then the data is correct.
Please let me know if this helps.
Kind regards.