DADS archive classification. Currently the available entries are full frame images (ffi), long and short cadence collateral files (CLL, CLS), artifact removal pixel files (ARP), background pixel files (BKG), Reverse Clock (RVC) and Ancillary Engineering data (ENG). Valid values include FFI, CLL, CLS, ARP, BKG, RVC, and ENG.
Each pair of CCDs comprise a module and corresponds to four output channels (two per CCD). Each output is read out by a unique analog signal chain (e.g. amplifier). 1 to 21
OUTPUT is an integer ranging from 1 to 4 describing one of the four output channels. An object can have a non-zero output number if it is off, but near, a CCD. Each module has four output channels (two per CCD). Each output is read out by a unique analog signal chain (e.g. amplifier). 1 to 4
CHANNEL is an integer ranging from 1 to 84 that uniquely specifies the MODULE/OUTPUT pair.There are 21 modules, each with 4 outputs for a total of 84 channels. 1 to 84