Sine/Frequency Sweep on PXI-5421

[Curtis]

I have been trying to set up my 5421 AWG to create a sine/frequency sweep, but all examples do not work. I was curious if there was a work around to make any of the examples to work, or if anyone knew how to set a sweep up with the 5421. Thanks in advnace.

[Jack_A.]

The 5421 is an Arb. The examples that you have probably been trying to use take advantage of the DDS on some of our function generators.

With the 5421, you can download any waveform you want as long as it fits in the memory of the board itself. Therefore, if you want to create a swept sine waveform, you can use LabVIEW's function generator VIs to do this and then download it to the 5421. I've attached a more advanced swept sine VI below that you may find useful.

We also have a program called the Analog Waveform Editor which provides an easy way to graphically produce complex waveforms.

Hope this helps,
Jack A.

[Curtis]

Thanks! I have another question now though. When I try to create a waveform with the output of the Timed Sweep VI, I get one of two errors.

First One: When I allow the Output data to be extracted from the input signal, the NI-FGEN Express picks up a Sample rate of 1. Is there a way I can incorporate the Sample rate into the array?

Second: I manually set the sample rate to the correct one within the Express properties, but I now get another error I cannont seem to fix. I get an error stating the waveform length is invalid, because the number of samples is not an integer multiple of the waveform length increment. The error message states the Requested Value is 160001 and the Waveform length is 4. My parameters used are Duration 4 sec, and Sampl
es 40K (S/sec)

[Curtis]

I fixed the Second problem by deleting the last element from the array, but I do not get an output signal from the actual card. The program runs without any errors.

[Curtis]

It works now, I am not really sure why it didn't work before.

There are some interesting issues though with marrying your program with the ARB Express. Nothing wrong, just some input values are not what comes out of the ARB. Easily fixed, but still I am very curious why they happened. If you are interested in what happened just leave a comment or email me.