Real time phase update of SimulateSignal

[MikN]

Hello there,

I am quite new to using LabVIEW. I am trying to adapt a program that has been written by previous collegues of mine. It concerns the synthesis of a square wave using the SimulateSignal VI. The current program takes an initial frequency and phase input and synthesises and outputs the signal.   My requirement is to allow the VI to have a user input for the phase angle, so that the phase of the square wave can be changed in real time. Thus the square wave may start out with a zero degree initial phase angle. After a time, the user will require an adjustment to the phase, but this must be done in real time so that the square wave is continually outputted. This is the important point of the problem. Any help would be tremendously appreciated. Many thanks,
mik

[Dennis_Knutson]

All you have to do is wire a numeric control to the phase input of the express VI and a Boolean True constant to the Reset Signal input.

[MikN]

Hi there,
many thanks for that. I will give it a go asap. Seems simple enough!

Regards,
mike

[MikN]

Hi there,

that has worked a treat. I can now update the phase in real time, and plot the output to a Waveform Graph.

And for my next trick....

Well, the key idea is that I have to send this square wave output to a NI breakoutbox (SCB-61), in real time. I have had a read, and it seems possible to do. I have a current version of the program that takes a '1 shot' input and then outputs it continuously while the program runs. I have attatched this section of the program. So, I'm not sure if it's possible to simply modify this, or if I should start from scratch. Any pointers? This image I've attatched is for a program that is also designed to simultaneously record an audio input. Again this is something I would like to be able to do along with the continuous output I mentioned earlier.

Any help is again much appreciated. I apologise for the newbish nature of this post. I just haven't had time to learn LabVIEW from the ground up yet. If someone could perhaps point me in the right direction that would be terrific.

Regards,
mike

[MikN]

Hi, I've been thinking about this today, and I reckon it's going to be easier to avoid a significant change to things. I have come up with a simpler method I feel. My only requirement is that, given the program I've attatched, how can I add a continuous until stopped recording button...? i.e. at the moment it records for a specified length of time, but I want it to continue capturing and recording until told to stop....

Regards,
Mike

[Dennis_Knutson]

To keep running your program, put a while loop around it and wire a Boolean control on the front panel to the termination terminal