12-27-2013 02:09 AM
I want to read Dmm and AI0 from NI Elvis II+ synchronously.
When I add the Sample clock, DAQ READ function returns the error -200279
"dmm.vi<append>
<B>Property: </B>RelativeTo
<B>Corresponding Value: </B>Current Read Position
<B>Property: </B>Offset
<B>Corresponding Value: </B>0
<B>Task Name: </B>_unnamedTask<1B>"
12-30-2013 11:59 AM
Hey Manushak,
Please see the following article on troubleshooting steps for your error:
http://digital.ni.com/public.nsf/allkb/AB7D4CA85967804586257380006F0E62?OpenDocument
Regards,
01-06-2014 11:01 AM
Hello Manushak,
There are a couple of issues with your AI0 acquisition. You should configure the timing before starting the task. Also, since the task is configured as finite, you will want to start (and stop) the task during each loop iteration. The defaults for acquisition timing are 1000 points at 1 kSps, but your read VI is set for a single point (maybe you did that intentionally when disabling the timing).
I've modified your VI and got it to work (see attachment). Keep in mind that this is software-timed coarse synchronization. The DMM on ELVIS can't be hardware timed and is pretty slow (a few updates per second), so you won't get millisecond-scale synchronization.
I hope this helps,
Charles Y.
National Instruments
01-08-2014 02:31 AM
Hello all
Thank you for help.
Ian says that "Attempted to read samples that are no longer available" it is one reason of my problem, but the main reason which Charles has noted is the mixing order of functions.
Here my final solution