waveform chart x scale

[rschmeling]

I am looking to have the time (x axis) on a waveform chart in 7.1 start at 0 for each run.  I have gone through and tried the settings and have it at relative time and I am trying to use a property node to set initial x value to 0 at each run however it is going from jan1 1903 in HR:MIN:SEC.  I would like it to stay in that form but like I said have it start at zero.  To clear the chart each time I have a property node set to history data and since labview 7.1 wont create a constant I have had to wire in a control and leave it blank.

[Joseph_Loo]

Try changing the X-axis to relative time

[rschmeling]

It is set as relative time.  Maybe the time is not the Jan 3 date but it is like 9 billion hours so I am assuming that it is that date.  In the core 2 class we do an exercise and do offset and multiplier, but that is not working and it is still coming up in that time.  Again this is 7.1 and all the classes I have taken have been in labview 10 so I am sure there is something that needs to be done different since it is the older version. 

[Joseph_Loo]

Then try setting it to floating point.

[Lea_D]

Hi rschmeling,

I see you're trying to configure a waveform chart in LabVIEW 7.1. Did you try Joseph's suggestion of the floating point number? That would be my next step as well.

If that doesn't help the problem, would you mind attaching your code, so that forum users can pull it up and look at it?

Lea D. 

[rschmeling]

I did try the floating point, and I am still getting some number that is 3E9 and change. 

[MKES]

Hi,

Here I attached a small VI (LV7.1) example where I'm using a property node to reset to zero (empty chart) every time VI runs... is that what you wanted to do?

About the initial value (0), leave floating point (default) as x-axis format and you'll get what you want.

... if I can help, I'll do it.

[rschmeling]

I have the history property node wired in to the sequence loop that starts the vi, but insted of creating a constant I had to create a control, 7.1 wont let me create a control for that data type.  with that It is clearing the chart but it is not setting the scale to zero.  The scale on the x axis is reading as strating at some number that is 3E9( it is set to flating point but I changed it to scientific just to get the exponent).  This is for an instrument that we have in the lab here and I am trying to set up the x axis so that is starts at zero.  

[Lea_D]

Hi rschmelling,

I had a chance to look into 7.1 a little bit. Since 7.1 is pretty old, I'm not very experienced with this. The core 2 exersizes that you looked at are for more current versions of LabVIEW, so the steps might help, but getting to them won't be exactly the same.

Looking at the waveform chart, the way the chart is, you can set it to start at zero, but as the program runs, it's going to scroll, and when the program is turned off, you can always go back to zero by double clicking on the number on the x-axis and typing in zero. 

There is another option to use the Waveform Graph; however, that is only going to show you one period at a time rather than the entire thing that you are measuring. I would definitely set the chart to the floating number as indicated above, but there isn't a way to get around the scrolling action. 

[rschmeling]

There should be a way to set it to zero pragmatically though.  I am not the only one using this program, and while I know a small amount regarding labview the other people know only how to open this program and wire up their detector to the daq board.