Wait Until Done error

[ampm]

Hi.

I am using 6704 AO and 6289 AI boards.
For 6704 I output a single value on four channels, for 6289 I read a single value from four channels.
The .vi files with the corresponding tasks for AO and AI are attached.
You can also see the AO task structure in the .PNG picture file enclosed.

The problem for both the AO and AI tasks:
if I use "Wait Until Done" vi after the "Start" one, I get the following error (see the "Wait Until Done error.PNG"):
"""
Error -200560 occurred at DAQmx Wait Until Done.vi:1

Possible reason(s):

Wait Until Done did not indicate that the task was done within the specified timeout.

Increase the timeout, check the program, and make sure connections for external timing and triggering are in place.
"""

What is the reason for this error?
How can it be avoided?
Is there any guarantee that if I do not use the "Wait Until Done" vi and call the "Stop" vi immediately after the "Start" one I will actually get the AO values at the output of the 6704 and my 6289 will have time to read the values?

Thanks in advance!

[rpursley8]

For the AO task, you auto start the task and then you also have a start task vi in there.  If you delete the the Start Task.vi, it will work.

[rpursley8]

For the AI task you should put the vis in this order

1. Start Task
2. Read Data
3. Stop Task

You do not need a Wait vi because the read will not return until the data is ready to be read.

[ampm]

Thank you very much!

Happy New Year!