Help! Need to generate a sinewave....

[Mr. King]

Hi everyone. I am new to Labview and must prove that using LV and a
data acquisition card that it is possible to produce a sinewave of
1kHz out of the analog out port and also be able to read in the
results thru an external filter to the analog input ports.

The other requirement is the sine wave must run continuosly for at
least 10 seconds without having an glitches from restarting the loop.

I have tried several vendors for acquisition cards and believe that I
need a card that has some sort of FIFO buffer. Anyone have any ideas
on how I accomplish all this? Thanks, Shannon

[Greg_McKaskle2]

> Hi everyone. I am new to Labview and must prove that using LV and a
> data acquisition card that it is possible to produce a sinewave of
> 1kHz out of the analog out port and also be able to read in the
> results thru an external filter to the analog input ports.
>
> The other requirement is the sine wave must run continuosly for at
> least 10 seconds without having an glitches from restarting the loop.
>
> I have tried several vendors for acquisition cards and believe that I
> need a card that has some sort of FIFO buffer. Anyone have any ideas
> on how I accomplish all this?

A FIFO buffer will help in this, but more importantly, you need
a driver for the card that supports a kernel level buffer that
can hold the points not stored on the card and access them at

interrupt time. Without this, you are trying to get the OS
to do something every 1ms, and that is too much to ask. There
will be times when it is busy and ignores you for 10ms or more.

If you are using NI-DAQ, there are icons for analog output,
or AO. There are single point AO functions for setting up
a DC voltage, and there are buffered AO routines so that you
can send the entire signal and set it to repeat.

In parallel, you can configure an analog input or AI task
that acquires and does whatever to the signal.

Better yet, you should be able to browse through the Solution
Wizard and find an example that does this or something close
right out of the box.

Greg McKaskle