LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

reading out from two DAQ and splitting the signals afterwards

I will use two DAQ. One will read out 3 signals, the other one 2. How can i make sure that the following order is 1 2 3 4 5 1 and not 123 123 ... ? How can i test it?
Afterwards how can I split all the signals?
Thanks ...
0 Kudos
Message 1 of 8
(2,881 Views)
Which DAQ card are you using?
If you are using E series, M series, DSA etc, you could synchronize and simultaneously acquire from both the DAQ cards
 
You could use array functions to append or split the data from both the DAQ cards as you want
 

How can i make sure that the following order is 1 2 3 4 5 1 and not 123 123 ... ?

That query, I cannot entirely understand. can you eloberate on it??
0 Kudos
Message 2 of 8
(2,874 Views)
Hi, thanks already.
 
I meant:
 
DAQ one has 3 signals to read in.
DAQ two has 2 of them
 
I want to read out simultaneously or at least the five signals very shortly after one another and not first the first DAQ and only afterwards the second
 
0 Kudos
Message 3 of 8
(2,859 Views)
This is possible.  If you were to create two tasks, one for each device, and then configure your input channels to be read in the order which you desire (you can add/delete/move channels in a task to be read in any order).

For instance, task A reads Channel 1, Channel 2, Channel 3, task A ends.  Use the error out of the DAQmx read which read Channels 1,2, and 3, and wire that to the error in of another DAQmx read, which has task B wired to the task/channels in input.  Put all of this in a loop, and you should get what you're looking for!

Unfortunately, you won't be able to read simultaneously, unless your hardware supports it.  Most DAQ inputs are multiplexed to remove the need to have multiple ADCs on the board.

EDIT: Splitting the signals is easy.  The DAQmx vi's are polymorphic, so that you can output an array of your 3 readings from task A, and likewise for task B.  And then you may play with the arrays to suit your needs.

Message Edited by Day on 10-02-2006 10:18 AM

Message 4 of 8
(2,850 Views)
Day has already explained the process
Just one detail i ask

I want to read out simultaneously or at least the five signals very shortly after one another and not first the first DAQ and only afterwards the second

Is this a finite or a continuous/Iterative operation that you would do?
Message 5 of 8
(2,839 Views)
Hi Devchander,

It's depending on your application !!!

If you want to run your acquisition one time or a certain time, you can play with the sampling rate and the number of samples and you don't need to have a while loop.

BUT

If you want a continous acquisition, you need to surround the DAQmx Read function by a while loop.

It's your choice.
Julien Roland - District Sales Manager
NI Belgium - Technical Support

Don't forget to rate a good answer
0 Kudos
Message 6 of 8
(2,822 Views)

Hey Julien,

Thanks for posting!

But looks like you misunderstood the context/ reference of my query Smiley Wink

I am already aware of what you are trying to say ( put DAQmx read in while loop for contiunous acq and that, it depends on my application)

That query of mine was directed to Rowena ( the person who posted this query) so that he/she may give more details and we could answer the query better! Smiley Very Happy

Regards,

Dev

 

 

Message 7 of 8
(2,806 Views)

Hi,

Thanks to all of you. I need the solution to run for a certain time. So not continuous. Problem is solved 😉

 

 

0 Kudos
Message 8 of 8
(2,800 Views)