sync e-series and high speed digitizer

[weizbox]

Im going to need to sync up my high speed digitzer and my e-series so they both get input data at the same time. I have a PXI-6025E as my e-series DAQ card and a PXI-5102 as my high speed digitzer. Both will need to take the same amount of time worth of data, but at different sampling rate, the digitizer at 20Ms/S and the DAQ at about 500ks/S. Dealing with the data afterwards isnt a problem, getting them both to take data and the exact same time is, im going to be looking at about a 10ms window at the least and possibly a 1 second window at the most. Please let me know if theres a way to do this, sure there is, Im just not really that wellinformed about being able to sync cards up.

Thanks you very much,
Mark Wiesbock

[Kevin_Price]

I've only got time now to outline some basic info; hopefully someone will fill in the gaps. I'll mention a few terms and concepts that you can find more info about either under the LabVIEW examples or here on the website.

1. RTSI: This timing bus ("this set of wires") is built into your PXI chassis so any DAQ boards you install are automatically connected. If you use traditional NI-DAQ, you'll be programming RTSI signals explicitly. Under NI-DAQmx, most if not all of that stuff is done for you "under the hood."

2. Sample Clock and Convert Clock: You'll want to slave these off of the timebase used by your high-speed digitizer to guarantee that the sample times for your boards remain properly synchronized. Note: under tradi
tional NI-DAQ, these are called "Scan Clock" and "Channel Clock."
Under DAQmx, these can be defined with the timing vi or the timing property node.

Good luck with the app; rest assured that indeed you can get there from here.

-Kevin P.

[Jeremy R.]

Mark,

There is an older (LabVIEW 6.0) example that shows how to do this. It might be worth modifying for your needs, but it should at least show you how.

http://venus.ni.com/stage/we/niepd_web_display.DISPLAY_EPD4?p_guid=B45EACE3E2C556A4E034080020E74861&p_node=175382&p_submitted=N&p_rank=&p_answer=&p_source=Internal

Best Regards,
Jeremy R.
NI - Applications Engineer

[weizbox]

Thanks for the link, altho I cant seem to get to it. Can you post it again?

[Jeremy R.]

The link seems to work OK for me. Try this:

1. Go to www.ni.com
2. Click the link at the top of the page for NI Developer Zone.
3. Now, in the search field type "e series digitizer"

The first link should be the document titled "Synchronization of a DAQ E Series Device or a NI 5102 with a High-Speed Digitizer (NI 5112 or NI 5911) using RTSI.".

Have a good day.

Jeremy R.

[weizbox]

thanks a lot, that method of getting to it worked great. I tried the link again and still wouldnt find it, very weird. Anyways, I took a look at it and it seemed like I can work with this . Thanks again!

[lfw]

Hi,

I am facing the same problem. Can anyone show me how to synchronise the sample clock of the 2 cards. I tried looking for the post indicated but could not.

Thanks.

Regards,

lfw

[Nicholas_B]

Here is the link to the external version of the document:  http://sine.ni.com/devzone/cda/epd/p/id/3227  

The previous link was to an NI-Internal-Only copy. 

Regards,

Nicholas B, National Instruments