analog output problem with AT-MIO-16XE-50

[Gene Couch]

I inherited one of these boards without any supporting documentation.
Have no problem using the AI or Counters but have been unable to
generate an analog output voltage. The catalog notes the AOGnd is
not used for this board.

How would you terminate an analog output. None of the analog output
vi's give an error, just cannot see the voltage on the output pins.

The only configuration option under the test panel is a drop-down
list with bipolar being the only choice. It doesn't seem that it requires
an extref voltage, or does it?

gene couch

[Umer Yousafzai]

The AT-MIO-16XE-50 uses AOGND as the reference for voltage output. In the
2000 catalog, the footnote says that the GNDs as well as the 2 DACoutputs
are not available on the DAQCard (PCMCIA) version of this product.

Try using the AOGND as reference and you should see the waveform. In most
cases, if your receiver instrument is ground referenced, i.e. not floating
with respect to earth, you should be able to see the voltage output without
directly attaching a ground wire (signal will appear noisy though).

If it still doesn't work, try measuring output voltage with a scope that
you've verified to work (wrap back probe calibration signal). Also, try
the second channel. It is possible, though unlikely, that one of the opamps
or the D/A converter is damaged on
your board.

Hope this helps.

Umer

[gcouch]

On 5 Apr 2000 14:37:11 -0500, "Umer Yousafzai"
wrote:

>
>The AT-MIO-16XE-50 uses AOGND as the reference for voltage output. In the
>2000 catalog, the footnote says that the GNDs as well as the 2 DACoutputs
>are not available on the DAQCard (PCMCIA) version of this product.
>
>Try using the AOGND as reference and you should see the waveform. In most
>cases, if your receiver instrument is ground referenced, i.e. not floating
>with respect to earth, you should be able to see the voltage output without
>directly attaching a ground wire (signal will appear noisy though).
>
>If it still doesn't work, try measuring output voltage with a scope that
>you've verified to work (wrap back probe calibration signal). Also, try
>the second channel
. It is possible, though unlikely, that one of the opamps
>or the D/A converter is damaged on your board.
>
>Hope this helps.
>
>Umer


Umer,

Thanks for the response. I thought I had tried this but you know how
that goes. Will give it another try next week when I have some time.

The basic test jig was something like:

DACxOUT ------SomeResistor-------gnd;AOGND;gnd tied to AOGND

On none of the 3 tested returns did I get a voltage across the
resistor. Or am I missing something about using AOGND as
some form of EXTREF (can't find anything about EXTREF
for this card.

Sorry about the long delay on the reply. I had actually given
up on a response and didn't check for a couple of weeks.

The help is appreciated.

gcouch