In the manual the description of the packed data format contains values that start with "G" in the upper nibble. What is that?
The values A1-G7 in the example represent
bits. It's an illustration of how the individual bits in a series of seven bytes are rearranged to be packed into eight bytes whose MSB must be 0. It's needlessly confusing since the placeholders they chose look like they're supposed to be hexadecimal values themselves, complete with a zero bit being represented by 00.