Same Sky's AMT21 and AMT22 absolute encoder series come in single-turn and multi-turn variations. Single-turn encoders provide positioning data over one full revolution, 360°, with the output repeating for every revolution of the shaft. Multi-turn encoders also provide positioning data over a single turn, but have an additional “turns” counter that measures the number of revolutions. In the AMT21 and AMT22 multi-turn versions, this turns counter is a 14-bit signed number plus two checkbits for error detection with a battery backup required to prevent loss of the turns count. The turns count is read in the same format as position and allows for -8192 to +8191 turns.