"Start Task" fails while using two task in parallel (DQMH CML)

[mw42]

Hello community,

since the acqusition is now working with my NI-9234 (in a NI-9185 chassis), I wanted to add a second card (NI-9215) and acquire signals as well (all with the DQMH CML Example Version 6.0).

In the Acquisition module, I changed the data cluster to have a second "DAQmx Task Name" (the first for my 9234, the second for my 9215).

But I do get an error, happening whithin the "Start Acquiring" case in the "Configure Hardware.vi":

Both my "DAQmx Start Task" fail with the following error message:

Error -50103 occurred at DAQmx Start Task.vi:7220002

Possible reason(s):

The specified resource is reserved. The operation could not be completed as specified.

Task Name: _unnamedTask<33>

 

I am not sure what I am doing wrong here, since I have those two "DAQmx Start Task" in parallel in other code as well. What am I missing?

Thank you.

Martin

[Gregory]

There are many possibilities, like having the resource reserved by NI MAX, or another module in your code. Can you attach your code here for a closer look?

[mw42]

Yes, my apologies for not posting the whole thing in the first place. Here you go 🙂

[Gregory]

Is there any chance you aborted the code before the task was stopped? You can try going into MAX and hitting the "reset" button when you select your cDAQ chassis.

[mw42]

I don't think that I aborted the task at any point.

It doesn't change anything after I reset the cDAQ chassis in MAX.

However, I do have some additional information. When I trie do run my acqusition I get these messages in the "CML Main.vi" message window:

37: Error code -200088 source: DAQmx Stop Task.vi:3590003<append> <DQMH>MHL Frame: Stop Acquiring</DQMH><DQMH>Event Handling Loop</DQMH> Additional Information: MHL Frame: Stop Acquiring
36: CML UI: Logger: Logging Stopped...
35: Error code -200088 source: Acquisition.lvlib:Acquire.vi<append> <DQMH>Helper Loop</DQMH><DQMH>Event Handling Loop</DQMH> Additional Information: Helper Loop
[...]
5: Error code -200088 source: Acquisition.lvlib:Acquire.vi<append> <DQMH>Helper Loop</DQMH><DQMH>Event Handling Loop</DQMH> Additional Information: Helper Loop
4: CML UI: Acquisition: Acquiring...
3: CML UI: Logger: File Initialized...
2: CML UI: Panel shown.
1: CML UI initialization succeeded.

Also I noticed that - when I press the STOP button within the CML UI Main - the aquisition stops BUT the STOP button is still active and the START button is grayed out.

Does this provide any useful information?

Thank you

[Gregory · Accepted solution]

Yes, it goes from most recent to oldest, so if you start reading from the bottom, you see the error starts at #5 in "Acquire.vi", with additional information to look in the helper loop. Now, I don't think there is any problem with the Acquire.vi, but take a look at how you wake up the helper loop, and see if anything needs to be changed now that you're using 2 DAQ tasks instead of 1 🙂

[mw42]

Oh my goodness, HOW could I have missed that. It is so obvious. Of course I forgot to update my "Wake Up Helper Loop" with the second DAQ Task.

Thank you for pointing that out. 🤗