Multifunction DAQ

Showing results for 
Search instead for 
Did you mean: 

On demand output

Go to solution
Is it possible to output a single data point on demand but with a sampleclock at 1000 Hz? So the loop itterates every 1 ms. So it is still hardware timed? I work with a USB-6211...

0 Kudos
Message 1 of 4

I came with this...


It works, but is it the right way?


0 Kudos
Message 2 of 4
Accepted by topic author ThijsBoeree

Well I think you can see that the code you have posted isn't quite what you were asking for in your first post.  One caveat with the code that you posted is that there is an 8k FIFO on the 6211 that will quickly fill up, leaving you a pretty large amount of latency (at 512 Hz, 16 seconds of latency).


The feature you would need to do what you described in your first post is called "Hardware Timed Single Point".  Unfortunately it isn't available on the 6211.  In general, USB isn't a great choice if you are interested in low latency single point applications.



Based on the example you posted, you'd be better off doing something like this:




There is no sample clock in this case though, so if you need exact timing between updates then this wouldn't be a good solution.  However, if the AO is just being updated to a new DC value based off of a UI slider then I don't see why a sample clock would be necessary.




Best Regards,

John Passiak
0 Kudos
Message 3 of 4

You're right, first i was going to aquire the generated signal from software, but now i'm going to hardware the output to an input channel, and then it doesn't need to be synchronised.




0 Kudos
Message 4 of 4