Start and Stop Trigger using PXI-6120 and DigitalStartAndStopTrigger.vi not working :-(

[GrahamG]

Hi Mike

Below I have attached a screen shot of the software I have running on my computer. Can you confirm that this is how you have  set yours up.

You will notice I have a second graph on my front panel showing a triangle shaped pattern. This is an indicator I added that shows my buffer filling and emptying on 3 separate runs of the program.

To recreate your system I have physically wired the digital out of the 6733 port0/line0 (pin 52) to the counter PFI0 of the Sseries 6120 (pin 11). I have also physically connected my input signal to chanel 1 (pin 33) (AI 1+) & ground (pin 32) (AI 1GND) of my S series.

I am using :

 LabVIEW 7.1

MAX 4.3.0f0

DAQmx 8.6.0f5

Trad DAQ 7.4.4f7

Therefore You are up to date. I do not think this problem is a driver issue though as I cannot see how your drivers would give this problem.

As an aside - why are you using two separate cards? Your 6120 has a digital out (pin 52) that you could use in place of the 6733 with no detrimental effect that I can see.

I think the next stage is to confirm that you have everything wired correctly and the system works before we start looking into your mass compiling issue. Mass compiling is non essential and I cannot see why you shouldnt be able to do it anyway as your set up should be fine. What is the DLL error?

Graham

[mm7376]

Hi Graham,

Okay, I've double checked all my connections and I'm 100% certain they are all okay... I've now got the following setup.

1) "Cont Gen Voltage Wfm-Int Clk.vi" running and generating a waveform on AO0 of the PXI-6733 card (named out).
2) "WriteDigChan.vi" running and generating a logic level on P0.0 of my PXI-6733 card (named out).
3) These outputs are wired to a dual channel scope and to AI0 and PFI0 of the PXI-6120 card (named in).
4) "DigitalStartandStopTrigger.vi" runs and stops at the correct time but never returns any data points.

Furthermore, I've now tested the following two other NI example VIs and they run as would be expected (see next post for images).

1) "Acq&Graph Voltage-Int Clk-Dig Start.vi" waits for the start trigger to be presented on PFI0 before capturing the finite waveform.
2) "Acq&Graph Voltage-Int Clk-Dig Start&Ref.vi" waits for the start trigger followed by the reference trigger to be presented on PFI0 before capturing the finite waveform.

As you can see AO0 must be connected correctly to AI0 and P0.0 must be connected correctly to PFI0 otherwise these examples wouldn't work.

However, I still have the original problem that the example DigitalStartandStopTrigger.vi doesn't return any data points.

Question... are all PXI-6120 cards hardware identical? I've seen that other NI cards with the same product number might have different internals (e.g. Korean FPGA versus other FPGA) and some of these have suffered from strange bugs that require firmware updates etc. Just a thought.

Mike

[mm7376]

Here are the other pictures due to the 3 attachment upload limit.

[reddog]

I don't have any real hardware to test with, but I think the feature of the device where it stores acquired data to onboard memory before transferring the data to host memory at the end of the acquisition is getting in your way here.  Try using the channel property node to set the data transfer request condition to onboard memory not empty and see if that fixes your problem.

Message Edited by reddog on 11-29-2007 09:51 AM

[mm7376]

Hi reddog,

Just added the property node you suggested and bingo it's now working perfectly!! absolutely brillient :-))

It works fine with either "Onboard Memory Not Empty" or "Onboard Memory More Than Half Full" - I think I'll use not empty for now until I've got a reason to change.

I can't say thankyou enough to both Graham and yourself for helping me on this it's been bugging me on and off for a couple of weeks now... I'm still not sure why I need to set this  property manually and on Graham's setup it just works (any ideas?) but I'm immensily greatful it's fixed.

Many many thanks,

Mike

P.S. Here are a couple of screen shots to prove it!

[GrahamG]

Hi Mike

I'm really pleased it works - also slightly mystified as to the use of this property node to amend the problem but if it works who am I to complain.

The confusing matter is why your memory was getting hung while mine was ok.

anyway, have a nice day.

Regards

[AnnaVerdi]

Hi,

I noticed this post from a while back seems to be exactly the same problem as I am now having, although I tried the addition of the property node suggested as the solution to the poblem above, but in my case it did not help.  

I was successfullly using the DigiitalStartandStopTrigger.vi from http://digital.ni.com/public.nsf/allkb/BA775B0E445BFA79482571FE0032CCEB successfully last year to acquire analog data from a NI-DAQ USB-6341 using a PFI trigger rising and falling edge to start and stop the acquisition.  However, I have recently tried to use the same code and I have seen that nothing at all happens.  It seems like Labview cannot see the start and/or the stop triggers anymore. As far as I know, nothing on my system has changed since the last time I used the code.  I am still using the same version of labview (2013) and exactly the same DAQ board. The connections are all good, as I can open NI MAX and see that the PFI port can be read as input (one of the 7 lines is active).  

Can anyone help with this?  I am a little bit desperate as I simply cannot see any reason at all for the code to stop working only a few months after it was successfully running.  Any advice or suggestions would be gratefully received!

Many thanks,

Anna