07-01-2016 03:21 AM
Hello Forum,
As I wrote earlier, I am trying to implement a two edge separation measurement that could be gated. In an updated version of an earlier program, I tried to use the pause trigger property node. However, I can't get it to work and keep recieving a -200452 error. Can anybody at least explain what is wrong the program (attached).
Regards,
RL
Solved! Go to Solution.
07-05-2016 03:49 AM
Hello,
You can see this link and check the solution.
I don't know which card you use, you can check if your card can support your pause trigger method.
Kind regards,
Lily
07-06-2016 04:17 AM
Hello Forum,
Thanks for your suggestions, Lily.
To answer your question, I'm using a 6321 X series DAQ card, a Perkin Elmer SPCM and a pulsed laser. I've followed your advice and useda pause trigger.
My code (attached) builds on two earlier examples. I have two questions:
1. It seems that if I do not use the Armstart trigger to start the two timestamp counters it doesn't work properly. Isn't the pause trigger by itself enough to synch both of them?
2. I'm trying to plot a histogram of the difference in detection times between the Start APD and the Stop APD. In the program, the data is collected in a producer loop and processed in the consumer loop. In the first TimeStamping_v2.i, I find the time difference by simply subtracting the time stamps in the producer loop. Ideally though, calculations should be done in the consumer loop. But as TimeStamping_v3.i shows, I can't quite transfer the data to the latter loop. It's probably trivial, but can any one help?
Regards,
RL
07-06-2016 08:24 AM
Hi,
Your card PCIe-6321 can support the pause trigger method, you can check the datasheet:
http://www.ni.com/pdf/manuals/374461b.pdf
But I think that you can just use the pause triggers in edge counting and continous pulse generation applications. Please see:
http://www.manualslib.com/manual/109451/National-Instruments-Ni-6238.html?page=97
So that's the reason you get the error -200452 when you use pause trigger for a two edge seperation measurement.
I find a VI in the exemple of LabVIEW and do some modification to show the error -200452 when you use the pause trigger.( no error when you use edge counting with pause trigger)
Kind regards,
Lily
07-06-2016 09:58 AM
Thanks again, Lily. I understand now why my earlier program doesn't work. My lastest program does use edge counting, but it still has a bug, which is passing data from the producer to the consumer loop.
07-06-2016 09:59 AM
Ooops, forgot to add program...
07-06-2016 10:16 AM
Hi,
See this.
kind regards,
Lily
07-06-2016 10:28 PM
Hi Lily,
Thanks for your very simple solution to problem of transferring data between loops. Thank you also for your overall help. The simple fact that others are taking an interest in your problem is enough to encourage one to keep trying until it's finished, even when it looks so hopeless at the start.
Kind Regards,
RL
07-07-2016 01:05 AM
Hi,
I'm happy that you progress in your project.
I get a lot of help from this forum also, the people can really help the others if they can.
Have a nice day.
Lily
07-08-2016 11:12 AM
Hi Lily,, Hi Forum,
Although my program works, it's far from perfect. One thing I read about the Edge counter is that it continues counting after the armstart trigger without reseting. Since I'm trying to timestamp the photons detected by the APD, is there a way to reset the counter? I tried to use the reset Edge counter node, but it appears that it is not compatible with the Pause trigger. Or am I doing something else wrong?