How to select signals from the output of a DAQ assistant

[cmorale4]

Hi! 

I am a new user of Labview 8.5 and I am working with a USB-6210. I have two different instruments connected to the same USB device, half of the channels are being used for pressure transducers where I only need to reed and save the data, while the other half are associated to TCD detectors where I need to perform some analysis to the signal to obtain and save the data. I am in the first step of building the block diagram, After I define each of the signals which its corresponding channel using the DAQ assistant, I need to select and separate the signals coming from the pressure transducers from those coming from the TCD detectors, before I can continue drawing the block diagram. I am trying to use the Select Signal function but I am not sure how to do this. Can anyone please let me know at least in which manual can I find a good explanation? I have been reading the Getting Started and the User Manual for LabView but they have not been very useful so far.

Thanks!

[SimonH]

Wire the Select Signals express VI to your DAQ Assistant and run the VI once (this allows the signal names to propegate).  Then when you open the Select Signals configuration you'll be able to pick out the channels you want by name instead of just "Signal 1" etc.

It sounds like you'll probably want two Select Signal Express VIs, one for the TCD detectors and one for the pressure transducers.  Something like this:

If you right click on the VI and select Help or click on the Help button within the configuration dialog you will bring up the LabVIEW help page for this (or any other) VI.  Are you looking for some other information that isn't documented in the help file?

Hope this helps,

Simon

[cmorale4]

Thank you Simon!

I am doing it the way you suggested. However, when I run the VI it seems like only one of the select signals VI is receiving the signals and providing as output the ones that I selected, while the other one does not receive any signals as I cannot see any output on that one. Also, why are you including a filter after one of the Select Signals VI, is it just an example? After I finished the block diagram the way you suggested, it tells me that I have a configuration that usually requires a loop. What is that about?

Thanks again!

[RavensFan]

Post your VI.  It sounds like you've wired up something wrong.

[SimonH]

The filter was just an example of some analysis you might do.

If you configure the DAQ Assistant to acquire continuously it will prompt you to put it in a while loop.  If you only want to acquire data for a short duration you can configure an N Sample acquisition and then you don't need the loop.

[cmorale4 · Accepted solution]

I fixed it. As you said, I had some errors in the wire but it is now working. Thank you so much for your help! It was very helpful. 

[RavensFan]

You should mark Simon's earlier post as the solution to your problem and not your own post.  First you need to unmark your post as the solution by going to the Options menu to the upper right of your message.