a/d units formula

[aduley]

I am trying to find out a formula to convert a value in volts to its
corresponding value in a/d units for a 16 bit data acquisition card. Any
ideas?

Thanks
Aaron Duley
____________________________________________
Aaron Duley / aduley@ufl.edu
Motor Behavior & Performance Psychology Laboratories
http://www.hhp.ufl.edu/ess/mblab
Department of Exercise & Sport Sciences
College of Health & Human Performance
University of Florida
(352) 392-0580 x1378
100 Florida Gym R-132-D
PO Box 118207
Gainesville, Fl 32611

[Albert.Geven]

Hi Aaron
can you give some more idea of the iocard ?
NI cards don't need such a formula, they simply need voltages

[Kristof Poppe]

I'm just thinking, but mayby you can try multiple dividing by 2

Aaron Duley wrote:

> I am trying to find out a formula to convert a value in volts to its
> corresponding value in a/d units for a 16 bit data acquisition card. Any
> ideas?
>
> Thanks
> Aaron Duley
> ____________________________________________
> Aaron Duley / aduley@ufl.edu
> Motor Behavior & Performance Psychology Laboratories
> http://www.hhp.ufl.edu/ess/mblab
> Department of Exercise & Sport Sciences
> College of Health & Human Performance
> University of Florida
> (352) 392-0580 x1378
> 100 Florida Gym R-132-D
> PO Box 118207
> Gainesville, Fl 32611

[Albert.Geven]

Hello Aaron
If you get the voltage from the card in a floating point number
in the range -10..+10 volt
you have to realize that +10 === 32767 and minus 10 === -32768
so to get again at the I16 number you need to multiply by 3276.7
and then convert the value to a I16

succes

[abrause]

A 16 bit DAC will resolve it's voltage output to 65,535 bits.

If the card is 0-5V, then divide 65535 by 5 to get a value

for 1 volt. (13,107)

So the formula for conversion would be: bits/13,107 = volts

To do it the other way, which is what it sounds like you want to do:

volts X 13,107 = bits

Hope this helps,

Alan

"Aaron Duley" wrote in message news:3a9f8dd1@newsgroups.ni.com...
> I am trying to find out a formula to convert a value in volts to its
> corresponding value in a/d units for a 16 bit data acquisition card. Any
> ideas?
>
> Thanks
> Aaron Duley
> ____________________________________________
> Aaron Duley / aduley@ufl.edu
> Motor Behavior & Performance Psychology Laboratories
> http://www.hhp.ufl.edu/ess/mblab
> Department of Exercise
& Sport Sciences
> College of Health & Human Performance
> University of Florida
> (352) 392-0580 x1378
> 100 Florida Gym R-132-D
> PO Box 118207
> Gainesville, Fl 32611
>
>