frequency output

[PowerNI]

Windows XP
LabVIEW 7.1
AT-AO-6

Hi,

I am going to create a vi to generate an signal as an analog output to test a Protective Relay, the signal should be:

1. Sine wave.
2. Around 5 V.
3. Around 60Hz.
4. Apply linear ramp to the output frequency, such that the frequency of the signal can vary automatically at a fixed rate. For example, if I want the frequency decay rate as 
    0.1Hz/sec, the frequency of the signal can change from 59.1Hz to 59 Hz in 1 second automatically, smoothly, continuously and evenly.

I modified Generate Continues Sinewave.vi, which can be found at:

the Generate Hardware Input andoutput > Traditional DAQ > Analog output > Generate Continues Sinewave.vi

and 1,2,3 works well. But I have no idea about 4. How can I Apply linear ramp to the output frequency, which can make frequency decay rate as 0.1Hz/sec

My vi is attached, which is not finished yet.

Any hint is appreciated.

Best regards

[PowerNI]

Any one can help me.

Thanks

[TheWoost]

Hi PowerNI,

You could incorporate the varying frequency in the built waveform to output.  There is a discussion forum post here that may provide you a good start on accomplishing this.

Another recommendation I would make is to use one of our Arbitrary Waveform Generators or Function Generators with the NI-FGEN drivers.  These devices are optimized for applications such as those that involve linear and logarithmic frequency sweeps and bursts.

Regards,
Andrew W
National Instruments