hello everyone I am working with an usb-1208fs (sinlge-ended mode,4channels, 12500S/s)and I want to use an encoder(100p/r) as extTrigger, when the encoder generate 100pulses (TRIG-POS-ENGE),in theroy I can get 100 numbers of data ,however when the encoder genetate pulses too fast (150pulses/s) I can get only 120 numbers of data.If the encoder generate pulses slowly((50pulses/s) I can get the same numbers of data(50). I have been sitting on this problem for two days and I have no idea what is wrong. I hope someone can help me. thank you | 
