several segment of one signal output as a undivid signal

[badstone]

Hi nice friends,

I'm working on some signal simulation with LabVIEW, all run well and just run into one signal problem.

It's a sinus signal, its frequency changes from 15Hz---30KHz smoothly. In the beginning, I thought it would be easy to construct a whole signal and output with the DAQmx Timing.vi (Use Waveform), but things seems not so simple, because of the big frequency(30KHz), I need make the sample rate of the waveform at least 300KHz, which still don't make the waveform smooth enough.

So I'm wondering, if it is possible to output the waveform as several segments and output them continuously. Still I'm wondering if it is possbile to make it with that big frequency(30KHz)?

Thank you all for andvance.

best regards

badstone

[GerdW]

Hi badstone,

limiting factor regarding sample frequency should be your hardware and not some SimulateSignal function.

Do you mind to tell us the DAQ hardware you have in use?

[badstone]

Exactly, NI PCI 6251 is what I'm using now.

I know the hardware sampling rate is fast enough, it's just because of the huge samples of the whole sinus signals which last 60seconds with frequency 30KHz(its sinus frequency, to make the signal clear, 10 times is already ), the computer cannot just construct it with low memory, so I want to separate it as several segments, but when I output them with DAQmx APIs, there must be some loop to repeat the "segment signals", and the loop is not fast enough, so there must be short DC values between sinus segments.

Or if there's some other better way to solve the problem.

I hope I made it clear, and thanks for your patient.

For more details, refer to attachment please.

[GerdW]

Hi,

can you please downconvert your VI to LV2011?

[badstone]

as you wish, thank you once again

[badstone]

I finally found the solution, thank you as the same.

[GerdW]

Hi badstone,

this forum lives by the solutions provided by users!

What is your solution (in case somebody else has the same problem)?

[badstone · Accepted solution]

Hi GerdW,

thanks for mention me.

I made a simple Block Diagram as follow

Idea is to generate a series samples(here is 100#s) of one periode sine signal, before output, set the sample clock as continuous samples and the start frequency 15Hz, then write it, the hardware will keeps wirte until the task is stopped or deleted. Now that the hardware keeps write this 100 samples, I change the sample rate with the DAQ Timing.vi in a loop, the frequencies change discretly.

I hope I made it clear.

best regards,

badstone