Analog output via DAQmx Assistant on NI 9263

[Eccomi]

Hello all:

I'm trying to power a piece of hardware and control certain inputs
using the NI 9263 device and the DAQ Assistant VI. I have previous
experience with data acquisition in Labview, but for outputs I am
admittedly a little stumped.

I found the following VI helpful for my setup:
http://digital.ni.com/public.nsf/allkb/44F1067EA1893DF586256F4D001A1E14

Modifying this VI was useful, but now I'd like to continuously switch
one input at a particular rate. How do I wire the data in to reflect
the (essentially) square-wave output I'd like to see? How do I change
the time-base for the analog output device?

I'm using all four analog outputs on the DAQ device, and the current
configuration I built has 4 bundles of 2 data values (max and min for
each output port, i assume) going into the data in connection on the
DAQ assistant. How do I change the dt attribute through this?

At one point, I had LabVIEW break the DAQ assistant VI down into its
omponents, of which I am using the setup vi containing the max and min
output values for each channel as well as some timing info. However,
altering this timing info does not seem to affect the output on the
device, so I am of the belief that I need to model everything using
the data in port on the DAQ assistant. Any help regarding timing
control on an analog output device usin LabVIEW would be immensely
helpful, thank you,

Daniel

[RavensFan]

The best thing to do is post whatever VI you have already.  It is hard to offer help when we can't see what you have.

[Dennis_Knutson]

The example you are using doesn't seem at all appropriate to what you want. If generates some static voltages. You are also completely mistaken about the min and max inputs. They set the range of your output. They do not set the actual voltage out.

You would be better off looking at the shipping examples for continuous output. You can generate a waveform (square, sine, triangle, arbitrary) and use the timing of the waveform data type to control the output.

You can learn some of the basics of data acquisition and DAQmx at the Getting Started with DAQmx page.

[ArchivedPointOnePa]

Eccomi wrote:
> Hello all:
>
> I'm trying to power a piece of hardware and control certain inputs
> using the NI 9263 device and the DAQ Assistant VI. I have previous
> experience with data acquisition in Labview, but for outputs I am
> admittedly a little stumped.
>
> I found the following VI helpful for my setup:
> http://digital.ni.com/public.nsf/allkb/44F1067EA1893DF586256F4D001A1E14
>
> Modifying this VI was useful, but now I'd like to continuously switch
> one input at a particular rate. How do I wire the data in to reflect
> the (essentially) square-wave output I'd like to see? How do I change
> the time-base for the analog output device?
>
> I'm using all four analog outputs on the DAQ device, and the current
> configuration I built has 4 bundles of 2 data values (max and min for
> each output port, i assume) going into the data in connection on the
> DAQ assistant. How do I change the dt attribute through this?
>
> At one point, I had LabVIEW break the DAQ assistant VI down into its
> omponents, of which I am using the setup vi containing the max and min
> output values for each channel as well as some timing info. However,
> altering this timing info does not seem to affect the output on the
> device, so I am of the belief that I need to model everything using
> the data in port on the DAQ assistant. Any help regarding timing
> control on an analog output device usin LabVIEW would be immensely
> helpful, thank you,
>
> Daniel

This group isn't widely monitored, so its best if you visit forums.ni.com

If you look in the NI Example Finder, search for analog and scroll down to the Gen Mult Volt Update - SW Timed.vi as an example. Alternatively, you could do the DAC updates based on a hardware timer, then then use the software timer to calculate your square wave frequency.

I don't generally use DAQ assistant as it has limited functionality, but looking at the GUTs of DAQ assistant should give you and idea of how to setup your own application.

Best if you select what your output update rate is going to be and fix that.
btw, why are you using an analog output for a discrete output? Also, what do you mean when you say, "I'm trying to power a piece of hardware".

[RavensFan]

---

PointOnePa wrote:
This group isn't widely monitored, so its best if you visit forums.ni.com

---

I'm not sure why you say this.  This message thread is on the forums.ni.com website.

[Eccomi]

On 7 fev, 19:55, Freelance Embedded Systems Engineer
<g9u5d...@yahoo.com> wrote:
> Eccomi wrote:
> > Hello all:
>
> > I'm trying to power a piece of hardware and control certain inputs
> > using the NI 9263 device and the DAQ Assistant VI.  I have previous
> > experience with data acquisition in Labview, but for outputs I am
> > admittedly a little stumped.
>
> > I found the following VI helpful for my setup:
> >http://digital.ni.com/public.nsf/allkb/44F1067EA1893DF586256F4D001A1E14
>
> > Modifying this VI was useful, but now I'd like to continuously switch
> > one input at a particular rate.  How do I wire the data in to reflect
> > the (essentially) square-wave output I'd like to see?  How do I change
> > the time-base for the analog output device?
>
> > I'm using all four analog outputs on the DAQ device, and the current
> > configuration I built has 4 bundles of 2 data values (max and min for
> > each output port, i assume) going into the data in connection on the
> > DAQ assistant.  How do I change the dt attribute through this?
>
> > At one point, I had LabVIEW break the DAQ assistant VI down into its
> > omponents, of which I am using the setup vi containing the max and min
> > output values for each channel as well as some timing info. However,
> > altering this timing info does not seem to affect the output on the
> > device, so I am of the belief that I need to model everything using
> > the data in port on the DAQ assistant.  Any help regarding timing
> > control on an analog output device usin LabVIEW would be immensely
> > helpful, thank you,
>
> > Daniel
>
> This group isn't widely monitored, so its best if you visit forums.ni.com
>
> If you look in the NI Example Finder, search for analog and scroll down to the Gen Mult Volt Update - SW Timed.vi as an example.  Alternatively, you could do the DAC updates based on a hardware timer, then then use the software timer to calculate your square wave frequency.
>
> I don't generally use DAQ assistant as it has limited functionality, but looking at the GUTs of DAQ assistant should give you and idea of how to setup your own application.
>
> Best if you select what your output update rate is going to be and fix that.
> btw, why are you using an analog output for a discrete output? Also, what do you mean when you say, "I'm trying to power a piece of hardware".

When I referred to powering a piece of hardware, I'm referring to
digital control of an RF switch (multiplexer) using the DAQ assistant
so that I can synchronize the switching time with the selected output
port for a simpler control setup.

I'm using an analog output because the 9263 only supports analog
output, although in truth I would prefer a digital one. Nonetheless,
the sqaure wave makes this a relatively easy transition.

Thank you for the advice on where to post my general questions; I'll
update if I run into any new problems.