xy graph cursor blinks

[user_1]

Hi All,

I have an xy graph and i cud find that the graph cursor always seems to blink....

I never had such a problem before...

Anybody knows solution for this

Thanks in advance

[altenbach]

---

user_1 wrote:

I have an xy graph and i cud find that the graph cursor always seems to blink....

---

Blink at a regular rate? Flicker?

How much data are you graphing and how often are you writing to the terminal? Are you autoscaling? Are you writing cursor properties?

Could you attach a smal demo that shows the problem? What is your LabVIEW version?

[user_1]

Hi,

Thank u so much for the reply...its blinking all the time ...not only in the loading time.Yes its having lots of data(but i dont think its the problem with data because previously i plotted many graphs wth much data...and cursor not causing any issue that time)...Yes am auto scaling by giving the value 2 to scalefit for appropriate scales.I was not writing to cursor properties...i have st graph cursor prope5rties(snap to all plots and bring to centre..that also statically...not thru coding).Sir i can not atach a demo as i cudnt stimulate this proble virtually...and if i have to attach..the vi ..that also currently not possible...

Kindly guide me on this

Thanks again

[S.AHMAD]

Hi,

I attached the screen shot and example VI for you.You can right click on the Curosr tool and select snap to cursor.MAy be you can send me the screen shot of your VI ,so can see what going on.

Regards.

Syed.

[Thomas_robertson]

Anything that can be done about this sort of thing?  Attached is my own scaled down version of this problem

[randoghsp]

Can you post as a VI snippet?  If not, will you post a back-saved to 2020 version please?

[pauldavey]

I would avoid updating the cursor list unless there is a need, eg. when some user interaction has occurred. Certainly there is no need to update it every loop iteration - it would be a terrible performance hog. Have a look at the Event Structure and also perhaps the Queued Message Handler (as suggestions) for your program architecture, and document the specific situations when the cursor list needs updating.

[Thomas_robertson]

In our application, the graph is updated several times per second.   The harmonic cursors need to be updated to reflect the latest y position of the graphs.   So, updating less often is not a problem.   The graph updates smoothly, but the cursors blink.

[randoghsp]

When updating, the previous cursor will disappear, and the new cursor will appear causing a "blink" on the corresponding cursor horizontal or vertical axis where the value changed.  If you are using a crosshair, then you will always see one or both cursor lines "blink" if any value updates.  You can minimize the jittery appearance by choosing to use a horizontal cursor when X values change the most or a vertical cursor where Y values change most often.

[lucian.grec]

This was solved here: https://forums.ni.com/t5/LabVIEW/cursor-flicker-in-graph/m-p/45961/highlight/true#M29095

You have to set smoothGraphMarkers=TRUE in your LabVIEW.ini file and potentially have smooth updates on and also your cursor needs to have the Allow Drag property set to false. This property is in the property node for the graph, under Cursor.
Same is valid for an executable.
The downside is that this won't allow you to move the cursor anymore. To do that you'll have to add some more logic to set Allow Drag back to True and back to False after you're done. Set it to true in Mouse Down? filter and back to false in the Mouse Up notify event.