05-11-2012 12:22 PM
I'd take a look at how you have your Analog Out of your ELVIS and Digital I/O configured for your scope. What is your sampling rate for these to for each of the frequencies that you are testing. You want to make sure you are sampling at least twice your data frequency.
05-12-2012 08:50 AM
The sine signal I used is at 50 Hz. The triangle signal is at 2000 Hz. I have done sampling for both signals at 20000 Hz. When I obtain the output at the analog channel of ELVIS, its frequency is 2000 Hz; same as theoretically expected. However if the output is obtained at the digital channel of ELVIS, its fequency is around 50 Hz instead of 2000 Hz.
05-14-2012 05:22 PM
Are you using Normal mode on the Elvis? The update rate of the digital output channel may not be fast enough to handle the 2kHz signal in this mode. Refer to this forum post for information on this: http://forums.ni.com/t5/Academic-Hardware-Products
05-16-2012 01:42 AM
While coding, I didn't change the default mode of operation of ELVIS. So It must be operating in Normal mode. I will post back after changing the mode and observing the difference in result.
06-02-2012 07:10 AM
I referred to the link you sent. I got to know that within the normal mode, we can output atmost a 1 KHz signal in the digital channel of ELVIS II. However I did not come across any material which elaborates on how to output higher frequencies. I will be very gratified if you could pin point a link.
Thanks & Regards
Post Graduate Research Scholar
Deptt. of Electrical Engineering
MNNIT Allahabad India