How can I plot time in seconds?

[flifl]

Hi, I have a little problem in ploting a graph versus time (x-axis)... I noticed that the time scale is not right, where the time is neither measured in seconds nor milliseconds. But it was every 50 units equivilent to 4 seconds (approximately), and I didn't change anything in its properties. What could be the problem? And how can I solve it? 

I have searched a lot in the forums, but I didn't find it in a clear discussion. Any help please?

Flifl, Labview2009-vista

[Dennis_Knutson]

If you are graphing a waveform data type, uncheck 'Ignore Timestamp'. Without the dt information, a graph has no idea what your sample rate is and defaults to a dt of 1. If you don't want to build a waveform data type, set the offset and multiplier properties from the front panek or block diagram. The example called Real Time Chart shows how.

[flifl]

Thanks for response, that was fast 🙂

First, I found 'ignore waveform Timestamp on axes' in the properties, but I can't check or uncheck it. All what I need to do is to plot a graph which has not a constant rate .. and make each 1 unit in the x-axis  indicates one second . I think it should be easy .. I am using the waveform graph indicator. Please, any help.

Flifl, Labview 2009, vista

[Dennis_Knutson]

No, you are using a chart as is clearly shown. As I already mentioned, the default dt is 1 second. And, whether you use a waveform graph or waveform chart, they can only display a  constant rate. Perhaps you want to use an XY Graph. That can display an non-constant x axis.

You could at least post an image of your code. The actual code would be even better.

[flifl]

Thanks again for the fast response .. I'm sorry, you are right, it was a chart ... But, the problem is as you said that the default dt should be 1 second. And as I told you before, I had each 50 units in the x-axis equivilent to approximately 4 seconds and I don't know why. And I need a constant dt equal to 1 second, that's all. So, what could be the problem??

My code is huge relative to the problem.. I will post an image of the waveform-indicator wiring. It's a motion tracker, simply I diffrentiate the x-path to get velocity then to get the acceleration. And each indicator in this shot is a waveform chart and in a while loop. All of them working together, but the problem is in the scale of the time as I mentioned. It's hard to adjust the scaling factor as I don't know each unit is exactly equal what in seconds. So, is there any advice? 

Flifl, Labview2009 vista

[Dennis_Knutson]

Well, how fast does your loop iterate? What sort of delay is there. I've already mentioned the example where you use the value of the loop delay to set the x axis timing.

[flifl]

Thanks Dennis, but can you show me the link of that example.. if you mean the real chart example, it was too late version and I got message that labview 2009 cannot open this file.. so is there any other example? And it would be better if the x-axis timing doesn't depend on the loop iteration time, if it could be..

Flifl, Labview2009, vista

[Dennis_Knutson]

Help>Find Examples. Then just go to the search tab and seach for Charts.