Error -200088

[FaisalF]

I dont know why I am getting this error each time I try to use my VI.

Error -200088 occurred at Driver Control (Voltage - Finite Output) (Version 4) Prescan 1.vi

Possible reason(s):

Task specified is invalid or does not exist.

What I am trying to do is to make two tabs for the waveform settings (in th VI attached) one tab outputs only tringular wave "prescan", the other tab "scan" that have a regular function generator.

 

Then after pressing continue on the error dialog the VI continuous with out stopping even if I pressed the stop button.

 

Please advice 

[FaisalF]

Here is the VI 

[warEagle12]

Hello!

After looking at your code, I believe your reference is getting dropped when you use a feedback node on your reference wire between your DAQmx Timing Property Node and your DAQmx Write VI. Feedback nodes are used in loops to pass data between multiple iterations of the loop (here is a good document for more information: http://zone.ni.com/reference/en-XX/help/371361H-01/lvconcepts/feedback_node_concepts/). Currently, your code is not running in a loop and therefore inputs null data at that point. If you place a probe before and after that feedback node and run your code, you will see the change in the value of the wire. I would advise taking all of these feedback nodes out of your system unless you are planning on putting all of this code inside of a loop, in which case you will need to initialize that feedback node as well. 

Thanks!