Error using start trigger on PXI-6143

[boto]

Hi All,

I am wirting to program that should have a synced an analog input and a digital output on PXI-6143 using Start Trigger. The trigger signal is set to use software trigger generated by an arbitrary waveform generator (PXI-5412). Please see the attached file for the program.

Somehow if I use either the "DAQmx Timing (SampleClock).vi" or the "DAWmx Start Trigger (Digital Edge).vi", the program will return an error saying:

Error -200452 ocurred at Property Node DAQmx Channel (arg1) in ...

The S-series manual didn't mention anything about whether or not PXI-6143 supports start trigger, so I am not sure if the device is really the problem or if I am making some mistake in the code.

If PXI-6143 doesn't support this function, could anyone please suggest a way to implement the code so that the start timing of the analog input and the digital output would be as close as possible?

Thank you very much!

[James-B]

Hi boto,

A couple of things I see all in the "Set Sample Rate" state.

- At the second NI-FGEN Export Signal VI, the value currently selected for the output terminal is not valid.  According to the FGEN help, to export on PXI Trig line 0, that string should be "PXI_TRIG_0".

- You are exporting the Marker Event from the FGEN to PFI0, but then trying to trigger off of the the marker event.  Is PFI0 on the FGEN connected to a PFI line on the DAQ card?  If so, try triggering off of that line instead.

Also, could you post the rest of that error.  It might give us a hint as to which function is failing / which inputs are invalid.

[boto]

Hi Jim,

Thanks for your suggestions.

The full error message from the original post is as follows:

-------

Error -2000452 occurred at Property Node DAQmx Trigger (arg1) in DAQmx Start Trigger (Digital Edge).vi:3->DO_error.vi

Possible reason(s):

Specified property is not supported by the device or is not applicable to task.

Property: Start.TrigType

Task Name: _unnamedTask<3>

-------

I also tried changing the code according to your suggestions, and here's what I found:

- I couldn't see "PXI_TRIG_0" on the drog-down menu, so I just chose the one the looks the most similar (PXI Trigger Line/RTSI0). Does this mean I am not exporting the clock properly? Is there any way to check if the clock is exported correctly?

- In the Set Sample Rate state, I tried to eliminate the niFgen Export Signal.vi and just trigger the AI and DO using MarkerEvent0, and it seems to trigger properly. However, when I actually export a MarkerEvent into PFI0 of the arbitrary waveform generator (like what was done in the original code) and connect it to one of the PFI lines in the DAQ card, and set the AI Start trigger to trigger from this line, it doesn't trigger properly. The error returned is:

--------

Error -200284 occurred at DO_error.vi

Possible resons(s):

Some or all of the samples reqyested have not yet been acquired.

To wait for the samples to become available use a longer read timeout or read later in your program. To make the samples available sooner, increase the sample rate. If your task uses a start trigger, make sure that your start trigger is configured correctly.  It is also possible that you configured the task for external timing, and no clock was supplied. If this is the case, supply an external clock.

Property: RelativeTo

Corresponding Value: Current Read Position

Property: Offset

Corresponding Value:0

Task Name: _unnamedTask<7>

--------

I really appreciate your help!

Boto

[boto]

Hi Jim,

Just wondering if you have had time to look into this further. I am still not able to fix this problem so far...

Thanks!

Wu-Jung

[James-B]

Hi Wu-Jung,

So in the "Set Sample Rate" state, you route the Marker Event 0 on th FGEN to PFI0, but you're still trying to trigger off of the Marker Event.  I may be incorrect, but I assume you have that PFI0 on the FGEN externally wired to an input on the DAQ card.  If this is the case, change the Trigger source to whichever line this is.

Also, it doesn't really matter, but is there a reason you are setting up the trigger in both the "Init" case and the "Set Sample Rate" case?  I was just wondering.

[boto]

Hi Jim,

Yes, I found these two errors and have corrected them a few days after the post. Instead of triggering off PFI0, I changed it to trigger the AI off the MarkerEvent0. I also tried exporting the MarkerEvent0 to PFI0 and connect PFI0 to one of the PFI lines of PXI-6143, and it also worked.

Setting up two triggering events in both "Init" and "Set Sample Rate" was just a mistake!

Thanks!