Iris AO has been developing a 489-actuator, 163 piston-tip-tilt segment, deformable mirror system controlled with a
personal computer. The system includes the MEMS-based DM, drive electronics, and a precision factory-calibrated
position controller. The position controller implements both position limiting to keep DM segments within the safe
operating region and calculates the actuator voltages that correspond to desired DM piston, tip, and tilt positions. This
paper describes recent speed enhancements and benchmarking results for the 489-actuator deformable mirror system.
Benchmarking showed an execution time of 157.5 μs from the start of the DM piston/tip/tilt (PTT) position controller
operation to when the last bit was output from the computer interface card to the DM drive electronics. Initial testing of
an asynchronous write operation for the computer interface card shows that the PTT controller function can return within
5 μs of a data transfer, thereby shortening the processor time required for a DM to an estimated 74.4 μs. All aspects that
give rise to latencies and bandwidth are presented herein, namely: 1) PTT controller safe-operating-point limiting and
voltage calculations; 2) computer interface and DAC latencies; 3) drive electronics bandwidth, and 4) DM bandwidth.