1 1 MODE INDICATOR (0 IF MODE 2, 1 IF MODE 1)
2 2 MODE 1 CALIBRATION SEQUENCE INDICATOR (0 IF NORMAL DATA TAKING EITHER MODE 1 OR 2, 1 IF MODE 1 CALIBRATION SEQUENCE)  'BITS 3 AND 4 INDICATE ACTIVE 23
3 3 CHANNEL 2 (0 IF ON, 1 IF OFF)
4 4 CHANNEL 3 (0 IF ON, 1 IF OFF)