NI 9401 How fast can I switch the output on off

[Geoff1]

Using a 9174 chassis and NI 9401 Digital I/O I can not get the output to switch faster then 10 ms. I would like to have the output turn on off @ 15Hz 9% duty cycle which would roughly be 6ms on 66ms  off. Does anyone have any idea how I could achieve this?

[crossrulz]

If you are using software timing (telling it to go high, then telling it to go low), you will not get the speed you want.  I'm not totally sure if it will work, but you could try setting up the digital outputs to output a waveform.  But you may need to go to a cRIO and use the FPGA in order to get the timing you want.

[Geoff1]

I tried a few different ways. One I simply had a couple of timers and some logic but once the pulse reached 10ms I could not reduce it any further. I also tried the output of a function generator but again was not able to get the pulse below 10ms. I will have to look into the cRIO and fpga at this point do not know much about it. Thank You for your help.

[Geoff1]

Actually I have another question if you do not mind me asking? Why is it I need the compact rio and fpga? The specs said 2 outputs should be able to switch at 20MHz so why do I now possibly need something different? Just trying to understand the situation. Thank You again

[Dennis_Knutson]

You have not attached your code but I'm guessing you the DAQmx Write set for 1 sample mode. That is a software timed output and not at all what you need for reliable and fast digital output. As mentioned, you should create a digital waveform and use n samples. See the shipping examples.