As written in the documentation, the DRS evaluaiton board has a maximum trigger capability of ~500 Hz. This is limited by the USB bus which has a finite data transfer rate. If you build your own electronics around the chip (like many other groups are doing), you can squeeze this to a few kHz, but it is some development effort.
I'm running a LIDAR application that requires that every outgoing pulse be captured. My current setup firess sets of 20-50 pulses at 1 ms intervals, about 10 times a second, but only 10-20 pulses a second are captured.
When I fire at full speed (1KHz - one pulse every ms), about 500-600 pulses a second are captured.
At the moment, I'm triggering on channel 1 and captureing the data on channel 2. Would it help if I used the external trigger? Is there anything else I can do?