Digital I/O

[xela75]

My question is very simple () :

Why NI does not design NiHSDIO drivers like that :When I synchronize 2 cards with a RTSI cable, the "system" sees the two cards as one card ?

For instance, x2 6551 cards with 20 I/Os seen as one card with 40 I/O ?

It will be more convenient that currently using Ni-Tclk, etc.

[Aaron_W.]

xela75,

Thanks for posting the idea on the forums. I know that there are often times when we do different operations with the different cards, example would be using one card for generation and the second for acquisition, but you would still need them to be synchronized together. Another option is to synchronize the two board, but use two different time bases for each card. Point being there are reasons why it might be better to keep them seperate.

Now DAQmx and the new X-Series Cards, as well as select other cards, can do what is called Channel Expansion and it allows you to use a single task or handle for more than one card. This is pretty nice, but it is limited to some of the DAQmx devices.

Overall, TCLK is a relatively simple implementation compared to all of the synchronization that is going on in the background. Below is a document that describes some of the behavior it does.

National Instruments T-Clock Technology for Timing and Synchronization of Modular Instruments:

http://zone.ni.com/devzone/cda/tut/p/id/3675

You could also provide Product Feedback on our website and this gets viewed by our R&D department. You will find the link to "Product Feedback" on the bottom left of the page below.

http://sine.ni.com/apps/utf8/nicc.call_me

[Aaron_W.]

xela,

You might also look at this community example that shows how to use a single HWS file to generate across multiple HSDIO devices.

HSDIO Multi-Device Dynamic Generation (TClk) One HWS File.vi

http://decibel.ni.com/content/docs/DOC-3982