The 16-bit CRC is encoded to 3 ASCII characters by using the following algorithm:
1st character = 0x40 OR (CRC shifted right 12 bits)
2nd character = 0x40 OR ((CRC shifted right 6 bits) AND 0x3F)
3rd character = 0x40 OR (CRC AND 0x3F)
The 3 ASCII characters are placed between the data and <cr><lf>. Parity is applied to all 3 characters, if selected for the character frame.
The CRC computation code is added to the end of the response, if the first letter of the command is sent by using lower case.