Multiple Inputs

[Du Bastos]

Hello,

I'm a beginner in LabView, and I take a Example on how to do a Single
Input Aquisition, it works perfect.

But I want to use 4 inputs (Physicall Channel is Dev2/a0; Dev2/01; so
on....), I tryed to simple "copy" and "paste" the objects, but it
doesnt work.

Do you know how to do it? Can you help me?

Thanks in advance.

Eduardo

[devchander]

Look at the attached example

It does a software timed, continuous single point AI acquisition on 4 AI channels

Here you can also specify how to address the physical channels

Hope this helps

Any doubts, do ask

Regards,

Dev

[David L.]

Hi Eduardo,

Devchander posted a great example for software timed, but I just wanted to footnote that you can also use ‘Dev1/ai0:4’ for the physical channel list. Also, the reason all of this is done in one task, and not 4 separate tasks, is because the card (unless simultaneously sampled) has one analog timing engine and one ADC which it uses along with a multiplexer to switch through the channels.

[Du Bastos]

I could not open the file because it is to Labview 8.2

I have onlye labview 8.0.

Do you have a way to save in 8.0 formant and send me the file to
eduardobastos@gmail.com

Thanks!!!

[David L.]

File saved in 8.0 below.

[unr]

Hi everyone

I have similar issue. I need to have 2 AI channels to take amplitude( Voltage in my case) values from the coupler connected to a power detector to get only the amplitude vaues continuously. I will have to work at the max. sample rate. ie my card USB 6259 support a max of 1.25 MS/s. Because the signal from the frequency generator will be in Mhz and that too at the higher side.when I use DAQmax assistance.vi the whole thing wont work even putting things in flat sequence.  What could be the easiest possible solution to get signal at the same time from the two ports without delay. I knw that DAQ card wont read both together unless u add channels to a task, becase of the ADC and multiplexer issues. error 510103......i am attaching the VI that I have. thanks for the help in advance.

Thanks

Sam

[Dennis_Knutson]

The VI you attached is corrupt and cannot be opened.

[unr]

oops sorry

[Dennis_Knutson]

Your VI is very confusing. You have one DAQ task with channels 0:15, you stop that, and then have a DAQ Assistant. I don't think the DAQ Assistant is starting a new task each time you run it so that would be one major problem. since you've used the DAQmx functions earlier, why not do the same thing if you want to start a new task? Is that what you really want to do? Acquire all channels at some rate and then acquire 2 channels at a different rate?

Your analog out is also incorrect because you are trying to start two separate tasks with the same resource. The sequence structure is doing nothing because you have nothing in the first or last frame and even if you did, dataflow controls execution order.

[bigrich68]

ya having same problem im using a NI USB -6008 DAQ and im trying to sample multiple analog voltage signals and display on front panel please help me lol a example program or walk through for the DAQ asssitant would help ty.