The spec for the 1200 says the AO rate is between 20 and 1000 samples/sec (system dependant). For a 50 microsecond resolution, you will need a more capable card such as the 6711 (4 channels @ 1 millions samples/sec). It is a common problem to underestimate the update rate required to generate waveforms. If your goal is to output, say, a sine wave at 10 kHz, you should count on 16-20 data points per sine wave period. This would require an update rate in excess of 160 kHz to output an acceptable wave form. With a resolution requirement of 50 microseconds, you would want to have a about 4 (or more) data points at each threshold to avoid "glitching" the device that is receiving the waveform. This would require a minimum update rate of 80 kHz.(Beyond the capabilities of
the 1200 series card).
If you want to maintain AI and AO capability in ONE card by simply replacing the 1200 card, you might consider the 6040E series board. It is spec'd for AI at 250 kS/s @12 bits and for 2 AO channels at 400 kS/s (non-FIFO) to as high as 1 MS/s.
