USB 6008 Digital Output Rate

[van990610]

Hi, 

I understand USB 6008 has software-timed digital output, but I was wondering what the maximum output rate for a digital signal is?

[Dennis_Knutson]

Depends on your OS, your pc, your code. There are some benchmarks for the 6501 which is also software timed. I would not count being any faster and could be much slower.

[Seth_B.]

Dennis is absolutely correct, because the USB-6008 only has software timed digital output, the speed of your output is completely dependent on the system.  Even on one system, it will vary based on the programs you have running.  If your virus scanner software decides to run a scan while you are acquiring, it could go from 150 Hz to 20 Hz pretty easily.  The other danger here is that unless you are monitoring the digital signal with an analog input channel or through some other means, it would not be readily apparent that the output had changed rates.  I would recommend a hardware timed USB device instead, such as the USB-6221.  This will allow you to use a hardware clock for your generation, making it much more reliable.

Regards,