Start timestamp - dynamic signal - waweform chart

[ethibault123]

Hi,

I have an issue with the start timestamp of an dynamic signal. I'm simulating a sine with the express signal generation. The thing is I can't reset it start timestamp (set it to NOW). The only way I found to do it is to stop my app... and then when I start the app again, the start timestamp resets to present time.

Why does this bother me? I'm plotting this signal on a waweform chart and I want to be able to reset to 0 (I mean, t0 =  now) the ''plotting'' of this signal without having to stop the application. I can't beleive there is no way yo acheive this.

Anyone knows?

Thank you
Eric

[majoris]

So many ways to do this.

You can replace that constant with anything to properly align your waveforms. Be it the current time, or just the default! You also don't have to plot the waveform as a waveform. You could just trip out the underlying array and plot it versus index.

I think the Waveform Timestamps Vi does this for you automatically.

You can get "Now" by using the Get Date/Time in Seconds vi.

What are you trying to achieve?

- Chris

[ethibault123]

Hi

Thx for reply, but it does not work... I had already tried to set current time to t0 through the ''build waveform'' and even the ''set dynamic signal attribute express'' VI.It only resets when I stop my app and restart it.

Here what I want to acheive:

I have an application running. On my mean screen, let say I click a buttom to perform a ''get signal'' process and show it on a chart. Once the process is over, bring me back to the main screen.

First time it works well as t0 is at 0 (now, current time). Once I come back to the main screen, I want to perform another one... but can't get my &?$%? signal t0 to ''now'', so my chart do not start at 0, it starts where it was at the end of the first process. I can't beleive it is so hard to do something should be so simple...

[majoris]

Try the Waveform Graph maybe?

[ethibault123]

I am 99% sure that the problem do not lie in the chart, but into the signal timestamp.

At the end, the chart is only a interpret of the signal... and will plot it as the signal is, time vs amplitude...

I have put an indicator on the signal start timestamp to monitor it, and whatever I do, it do not reset to ''now'' until I stop my app.

[majoris]

I just want to be clear that you understand the difference between a Waveform Chart (appends waveforms over time) and a Waveform Graph (plots on the data wired to it). If you do, then yes I agree. But it sounds like maybe you want a graph instead of a chart. I'm just not sure!

Otherwise, I'll just need to see the vi.