How to synchronize two devices with DAQmx base 2.0 (mac osx)

[tibobo]

Hello,

NI released the new daqmx base 2.0 for mac few days ago.
A lot of people asked for it, now it's real : we can do multithreading on ni devices with labview on mac !
I installed two M series device in my G5, made a tiny vi with two AI tasks running in parallel on each device, and everything's running all right.

I'd like to synchronize the samplings (triggering and/or sharing sample clock).

I read it's impossible to use RTSI terminal with DAQmx base and that we could use PFI.

Did anybody ever try something like that ?

Thanks

Boris Matrot

[AlanArmstead]

Hello tibobo,

You should be able to use RTSI, as long as you have a RTSI cable connecting your two devices.  With NI-DAQmx Base 2.0, you can use the DAQmxBase Export Signals, and export the sample clock from your "master" device to a RTSI pin ("/DevM/RTSIy", where M is the device number for your master device and y is an available RTSI pin).  Then on your "slave" device, set it up to have an external clock, with the source being the RTSI pin that you exported the sample clock to ("/DevS/RTSIy", where S is the device number of your slave device and y is the same number as before). 

-Alan A.

Message Edited by Alan [DE] on 01-20-2006 01:32 PM

Message Edited by Alan [DE] on 01-20-2006 01:33 PM

[tibobo]

Hi Alan,

Thanks for the detailed procedure and sorry for the late answer.

I'll try it on monday asap, and post if it worked.

Did you test it with a Mac ?
If you did and that it's not working for me, I'd be sure to be a LV looser !...

Thanks again.

Boris

[AlanArmstead]

Hi Boris,

I haven't tested on Mac.  I have tested all the necessary functions I mentioned above (on Windows).  However, there shouldn't be any reason it wouldn't work on a Mac.  If you try and can't get it, you might post your code so I can take a look.  Good luck!

-Alan A.

[tibobo]

Hi Alan,

I forgot I haven't got any RTSI cable !
I'll order one asap, test it, and post a detailed procedure for other mac users.

Thanks again for your help.

Happy independent-platform wireworking !

Boris

[AlanArmstead]

Great!  I'll look forward to hearing how it goes 🙂

[tibobo]

Hi Alan,

Well, I tried RTSI sample clock sharing with my boards. Unfortunately, nothing works . It's hard to know why (no error code as far as I remember).

I found that RTSI sample clock sharing is not supposed to work on mac osx here :
http://zone.ni.com/devzone/conceptd.nsf/we...256FB1007227EC

I also tried triggering (to launch acquisition on both boards simultaneously) and it didn't work too. I never read that it shouldn't...

In DAQmx base example, there is no hardware triggering example nor RTSI example. There is an example of Software triggering... which is probably the only solution I have left... but which is not really satisfying...

If somebody have any trick else than Soft triggering, please let me know !

Thanks for advices anyway !

Bye
Boris

[tibobo]

Here are trigger and RTSI VIs I tried.

Boris

[AlanArmstead]

Hi there.
I just tested with 2 M Series boards on a Mac OS X, using the RTSI program you posted, and everything worked fine.  Do you have an NI RTSI cable, or are you using another cable (some cables of that type swap some lines)?  Can you look at the signal on RTSI1 to see if it is there?  When you run it, do you get any errors?  What devices do you have? 

Also, could you post the full link that says you can't export to RTSI on a Mac?  If it does say that, it is now incorrect (that was correct prior to the DAQmx Base Export Signal VI, so it might just be dated).

-Alan A.

[tibobo]

Hi Alan,

"I just tested with 2 M Series boards on a Mac OS X, using the RTSI program you posted, and everything worked fine."

I didn't mentioned I tested it with one M serie and one S serie board. It could explain it didn't work for me.


"Do you have an NI RTSI cable, or are you using another cable (some cables of that type swap some lines)?
Yes, it's an NI RTSI cable.


"Can you look at the signal on RTSI1 to see if it is there?"
I didn't. I wasn't sure to be able to see anything. Anyway, I don't have any oscilloscope, but I could do it with the analog input of the other board !

"When you run it, do you get any errors? "
I get a "timeout" error from dev2 read vi.

"What devices do you have? "
M serie PCI 6284 and S serie PCI 6143


The link to the ni webpage
http://zone.ni.com/devzone/conceptd.nsf/webmain/42B73A7B82F0FEC786256FB1007227EC

I'll check if I get something on the RTSI1 port on monday.

Thanks for the help !

Boris