DAT Bits (8, 12 Low, 12 High, 16)

Controls: DD/Open >> DAT Format >> Bits
Macro : DATbits=8, 12Lo, 12Hi, 16

Use these radio buttons to tell Daqarta the size of each data sample. 12-bit samples are always assumed to occupy 16-bit data words, so there are separate buttons to specify whether the data is justified to the low or high end of the word. Multi-channel 12-bit laboratory-type data acquisition boards often insert the channel number in the otherwise-unused 4 bits.

If you don't know the actual number of bits used by the file, you will have to guess. Note that 12-bit High and 16-bit will give very similar results at high signal levels; at low levels the 12-bit data will appear more quantized since it has 4 bits less resolution. You should probably try setting 16-bit first, since if it is really 12-bit the worst that usually happens is that the low 4 bits hold some constant non-zero value like a channel number. This simply adds a tiny vertical shift to the data.

See also File Menu, Open Existing Data File, .DAT File Format Dialog