Unlike SXT, HXT is operated in a single observation mode (except for
calibration). When the Sun is quiet (i.e. in the quiet-high or quiet-medium
mode), only hard X-ray count rate data in the lowest energy band (L band; see
section 2-2) are telemetered once in every major frame (e.g. 2-s data
accumulation in high-bit rate). When the flare-high mode is (automatically)
triggered by the occurrence of a flare, then count rate data in the four energy
bands, with a 0.5-s data accumulation, are telemetered to the ground.
In this case, four sets of data ((64 SC's 
4 energy bands) 4) have their
telemetry allocation in one major frame.
When the spacecraft is in South Atlantic Anomaly (SAA) or in spacecraft night, high voltage supplies for the detector photomultipliers are reduced and no solar observations are made with HXT.