BUG: XScale.Multiplier is not working (LV 7.1.1)

[beatz]

I use the Waveform Graph to display data with an offset and a scaled x-axis. This works well as long the VI containing the graph is displayed.

In our production environment, the VI is closed and only called in the background during measurement. The resulting graph is later viewed using the web browser plugin. Now some strange effects occur. The data is displayed well but the scale is has a wrong scaling. The offset is ok but the multiplier is reset to 1 and therefore the scale is wrong.

As mentioned before this happens only if the VI is viewed or reviewed after it has been run. This happens even in the normal display, not only trough the browser plugin. BTW same effect with the Intensity Graph ...

Regards, Beat

[tst]

You should post an example of this (the smaller amount of code, the better).

[beatz]

You have to create a html file using the web publishing tool from the measure.vi. If you open the html file before running main.vi the x scale is ok (-5.0 to 5.0). If you open it while running the scale is wrong (0 - 40).

Regards, Beat

[tst]

I'm confused, is this behaviour only showing up in the browser? If not, why did you write to use the plugin? In any case, please write a step by step description of how to recreate this. I opened the VI earlier from within LV and the scale was -5 to 5. When I changed it manually it was -5 to 35.

[beatz]

Uuups, i just discovered that this happens only if the VI is running on a real-time target. Therefore this bug seems to be related to LabVIEW RT.

The steps to reproduce the bug:

- From the host PC: open LV and switch to the RT exection target
- open main.vi and run it
- open the Web publishing tool and create a web page for the measure.vi
- store the web page in the www directory on the RT target
- on any PC with the browser plugin installed: open the web page from the RT target

- the x scale is wrong
- stop the vi and restart it
- the x scale is correct

[tst]

At the moment I don't have an RT target with 7.1 installed, but from your description it sounds like you're right and it is a bug. What happens if you let the VI run independently on the target and connect with LV instead of with the browser? Is it displaying the same behaviour?

[beatz]

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@tst wrote:
At the moment I don't have an RT target with 7.1 installed, but from your description it sounds like you're right and it is a bug. What happens if you let the VI run independently on the target and connect with LV instead of with the browser? Is it displaying the same behaviour?

---

Yes, its the same behaviour. It seems that graphs are only drawn if they are opened somewhere (LV or plugin). If they are run in the backround and viewed later after the vi has finished working even the data is not displayed. Is there some code optimization which affects the graphing?

[tst]

Looks like you're right. I just connected to one of my apps running an a Fieldpoint 2000 that has a chart on its FP and the chart only starts updating when I connect. I guess this is in the LVRT engine by design, to save resources. Try reporting it to NI, but I'm not sure it will be changed.

[beatz]

Realy? In our application the Charts work well only Waveform and Intensity Graphs have this problem. For intensity Graphs at least the data is displayed but the scales are wrong. Very strange...

[tst]

No. Sorry, you're right. I must have made a mistake earlier.
I just tried it again and the chart does seem to update when I'm not connected.