analog output?

[guide chipy thingy]

hi!

i am writing a battery testing program for my uni's solar car team and
i need to output how much current is charged or discharged through the
battery. all i have to do is output a certain voltage and the
load/power supply will receive this voltage and convert it to current
using some scale. however, when i go in labview help about "AO update
channels", it says, about the input values:

"values is a 1D array that contains the analog output data expressed
in the physical units of your signal. You must supply this data. If
you are using channel names, the data should be expressed in the
physical unit you specified for the channel names in the Measurement &
Automation Explorer. If you are not using channel names, the AO-2DC
require A for the current unit.
All other boards require mA for the
current unit."

so i am outputting a current????????? i'm confused,i'm not sure how to
work with that.

be aware that i have been learning labview for the past month, and
that i am in my second year in mechanica engineering.

thanks!

philippe

by the way, the board we have is a BNC-2120.

[waldemar.hersacher]

Hi Philippe,

first BNC-2120 not a board, it is a connector to a board which has BNC connectors on its front and a connector for a cable to a E-Series card.

second there are boards which can produce voltage or current at the channel. If you configure the channels with MAX (Measurement & Automation Explorer) you can enter scaling of the values you use at "AO update channels" and the values which the card will give out.

third the AO-2DC is a card which has channels which work as current output. The SCXI-1124 has also current output. But the scaling is different. If you want 10 mA you have to give 0.01 to "AO update channels" for a AO-2DC and 10 for a SCXI-1124.

I guess from your connector that you have a E-Series card and you haven't configured cha
nnels with MAX. E-Series card will always have voltage output. So if you give 5.0 to "AO update channels" you will get 5 Volt on the output.

I hope this clears your questions,
Waldemar