XY Graph Cursor Problem in Labview 7.1.1?

Hallo,
I am using Labview 7.1.1 and I am facing one problem with XY graph cursor. If I am moving cursor in one graph, I am expecting same movement in another Graph. But when I move cursor in Graph1, cursor in second graph moves but not to exact X value of Graph1.
Property of Cursor in both graphs must be "Lock to Plot"
If any body knows about this please let me know ASAP. I am attaching example VI for your reference.
Thanks,
Sashi
Attachments:
XY Graph Cursor Problem.vi ‏101 KB

It's a curious effect. Probably the floating point coordinate is sensitive to the exact pixel alignment (I mean that this would not happen if we had for example 1 pixel per point in the X direction).
Anyway, if you use Cursor Index instead (which is an integer) the behaviour is as expected.
Paolo
Paolo
LV 7.0, 7.1, 8.0.1, 2011

Similar Messages

Problems in using graph cursor

Hi all
I have two questions
1)
I have a Graph control which has two cursors , cursor no 1 and cursor no 2. The range of X
and Y axes is from -20 to +20 each. I dont want to plot any waveform on this Graph.
I just want to place the cursors on the specific points within the range of x and y axes.
In this case, i am using
SetGraphCursor(PanelHandle,PANEL_GRAPH, 1 , 10.0,5.0); // Cursor number 1
When i run the program, the cursor does not move to the ( 10 , 5 ). Why is it so?
I have tried the Graph as a control and indicator mode , but the cursor does not move to the specifed position.Why?
2)
If the cursor 1 reaches to the certain position on the graph then i want that cursor 2 also reaches to that position by moving slowly and gradually on the graph and finally reaches the cursor 1 position. I want that it reaches the cursor 1 position in 5 seconds.
How is it possible?
Any Help will be greatly appreciated.

Here there is a little sample project that moves one graph cursor to reach the second one. It may be improved a lot: for example it can be modified to move the cursor a fixed lengh each step (now it splits the calculated routed in a fixed number of steps so that for long routes you see the cursor moving in steps, for short ones you see a more fluid movement). Consider it a conceptual framework that you may adapt to your actual problem.
Hope it may help you.
Proud to use LW/CVI from 3.1 on.
My contributions to the Developer Zone Community
If I have helped you, why not giving me a kudos?
Attachments:
MoveCursor.zip ‏6 KB

XY Graph cursor Error

Hello
This error was found, when I started using LabView 8, with my old LabView 6.1 VI's.
I have encountered a minor error on my Graph display. I noticed my Y-Scale numbers go negative, if I Press and Hold my Graph cursor, while I am moving it.
I run this same test using New LV 8 XY Graph and numbers do not go negative, but they surely flicker a lot + numbers still change some.
Have you noticed this before? Is there some new property I need to set up, to make my LabView 6.1 Graph stable? Is this known bug or am I just doing something wrong?
Here is VI for your testing. My LabView 8 version is 8.0.0.4005.
Just run it and while moving yellow cursor (press+hold+move), after 1-2 seconds of holding something happens.
Yours
Kari
Attachments:
Cursor Test.vi ‏84 KB

Hello Karik.
I experience the exact same problem in the application I'm programming.
The only solution I have come up with is having the cursors Y-axis
centered in the visible area of the graph.
However this is really bad because there is will create a smal "hole"
in the cursor bar, it looks awfull. I think this is a bug in lv8 since
in lv7.1 I could tie down the y-axis to like -10000 or something and
the problem would not appear.
Hope NI fixes this problem really really soon.
//Andreas

XY graph cursor position bug

I have reproduced the bug mentioned here:
http://forums.lavag.org/Graph-Cursor-XY-Position-Bug-t1366.html&gopid=40859#entry40859
I've reproduced this bug (?) in Labview 8.5, with an XY graph doing
much the same as Jack. The attached zip file contains a stripped down
version of my program (originally written by my coworker, Andrew
MacDonald). Run "RENA3 Data Viewer.vi" and follow the instructions.
As Jack said, changing Cursor.PosX to Cursor.Index solves the problem.
I did not find this bug mentioned anywhere other than the above link.
Fraser
Attachments:
XY Graph Cursor Bug.zip ‏142 KB

Hi Karla,
Sorry if that wasn't as obvious as I thought! :-) Hopefully the attached image makes it clear. On the front panel, 'Cursor Channel' is inputted. This is directly wired to Histogram.Cursor.PosX. Immediately following, Histogram.Cursor.PosX is read and wired to the front panel indicator 'Cursor.Cursor Position:Cursor X'. There is always a difference of 15 or 16 between the two values. If there was no bug, these two values should be identical! I can only conclude that Labview is doing something funny...
As I mentioned before, changing Cursor.PosX to Cursor.Index fixes the problem.
A bit of background: my FWHM function outputs the peak channel, and the cursor is supposed to go through the peak so you can have a visual check that it is analyzing the right peak. I noticed that the line would never go through the peak; the line would always have an offset. After wasting a couple of hours, it became clear that I was wiring the correct value into 'Cursor.PosX', but something was going wrong beyond that.
Cheers,
Fraser
Message Edited by fjharris on 01-25-2008 11:34 AM
Message Edited by fjharris on 01-25-2008 11:36 AM
Attachments:
Labview Bug.png ‏27 KB

Qucik Graph Cursor Legend Questions

Hi all,
I have a couple of quick questions regarding my graph cursor legend:
1. Is it possible to move the position of the cursor legend during runtime? I cannot seem to drag it around the graph?
2. Can I hide/remove the cursor mover? This is not needed and is for this vi as I need to be able to manually drag the cursors only.
I am accessing the cursor legend during runtime through a right-click and selecting "visable items:.
Thanks,
Jack

Hi please check Using Cursor Legend in this link if it is helpful
http://zone.ni.com/reference/en-XX/help/371361J-01/lvconcepts/customizing_graphs_and_charts/
Sorry i don't know exact answer for questions, But did you try property node of Cursor.
-To access it, right click the graph indicator in Black Diagram and go to create>>Property Node>>Cursor.
-Lot of options regarding cursor available there, you can make selected property to write or change the parameter. and check this for help on cursor properties
http://zone.ni.com/reference/en-XX/help/371361J-01/lvprop/cursor_p/
Thanks
uday,
Please Mark the solution as accepted if your problem is solved and help author by clicking on kudoes
Certified LabVIEW Associate Developer (CLAD) Using LV13

Unknown graph cursor tool

I'm hoping someone can identify a graph "tool" that's interfering with my LabVIEW program. It's not on the normal graph palette and I can't find reference to it anywhere. It activates seemingly on its own during runtime, and sticks around if I abort execution (its behavior appears to be coded into the graph itself). I wasn't able to take a good screenshot of what the pointer looks like when the tool is active, so I've included a scaled-up drawing below (pointer is the black/white parts).
Some additional details:
- It usually activates when the mouse point hovers over one of the cursors on my XY graph (but only under certain conditions that are not 100% reproducible). The graph cursors are free dragging, and the tool has only activated when I had more than 1 plot on the XY graph.
- If I click on a graph cursor when this tool is active and drag in either the +/- Y direction, the Y scale min/max values change to seemingly random values and the Y scale begins scrolling up. Nothing happens if I move the cursor in purely the +/- X direction.
Much thanks in advance.

Okay, I've been able to reproduce the problem consistently in a much simpler VI (attached). It only contains is a single XY graph, with no code on the block diagram. There's some data saved on the graph, and I put a bunch of cursors on it. When I follow the steps below, I've been able to reproduce the issue 100% of the time.
I should note that I'm using LabVIEW 2014 Professional (64 bit) on Windows 7.
Attachments:
Test.vi ‏118 KB

Unexpected Windows cursor/Waveform Graph cursor behavior

Hi,
I got a very strange Windows cursor behavior with waveform graph. Simplified VI is attached.
LabVIEW 2014 SP1
The problem is:
The VI contains only one waveform graph.
1. I start the VI. Cursor Movement Tool is selected in the Graph Palette by default. Corresponding “Cross with dot” Windows cursor appears when mouse is moved over the plot area (see image). So far so good.
2. I select Zoom in the Graph Palette and use it two-five times (second image).
3. I select Cursor Movement Tool in the Graph Palette again but Windows cursor does not change as it should. It is an open cross now (third image); i.e. the same as shall appear when cross of Graph Cursor Lines is reached.
4. I click mouse three-seven times anywhere in the plot area and the cursor becomes normal (as in the first image).
The problem is not only in shape of the Windows cursor. The whole Graph cursor functionality does not work properly if the Windows cursor has the wrong shape.
Please advise what could cause this problem.

It seems, i cannot explain the question in good way
It is not about my data or zooming. It is about strange bahaviour of the Graph. The following sequence of steps illustrates the problem and shows that the zooming is not the issue (or, at least, not the main issue):
I do the following:
1. Start the VI.
2. Select first Graph cursor in Corsor palette and use pop-up menu "Bring to Center".
3. Zoom couple of times (not too much) keeping the Grapg cursor visible.
4. Select Cursor Movement Tool in the Graph Palette.
5. "Open cross" Windows cursor appears from the beginning. I cannot pick up the Graph cursor.
6. Click left button of the mouse several times in any poin of the graph area.
7. Windows cursor is changed to the normal "cross with central point".
8 Now I can pick up the Graph cursor.
I would suspect problems with zoom until p.5. However p.6-8 are done without any change of the zoom.
By the way, I found more:
If I try to move the Graph cursor after p.5, the whole graph moves and fires event "Scale Range Change". It must not happen with Cursor Movement Tool selected.
I can guess only about some strange setting of the graph. May be I am not aware about them

How do I get an event-based response to a graph cursor change?

I want to respond to the user moving a cursor on a data (X-Y) graph. (LV 7.0)
What I really want is an event called "Graph.Cursor.Value Change", which would supply me with the new coordinates, but I see no such event.
If I use the MOUSE MOVE event to trigger obtaining the cursor values, it does not give me an event, until the cursor has stopped moving, the button is up, and the mouse moves off the cursor line.
Sure, I could use a TIMEOUT event, and read it every 100 mSec, but I don't like the time lag.
What I did was to set a flag TRUE on Graph.MouseDown and FALSE on Graph.MouseUp. I then choose an event timeout of 10 mSec or -1, depending on that flag.
That works, but is there a more direct way that I'm missing?
Steve Bird
Culverson Software - Elegant software that is a pleasure to use.
Culverson.com
Blog for (mostly LabVIEW) programmers: Tips And Tricks

No, unfortunately there is not.
To code around this limitation, I typically use the timeout event in a more complex way as follows:
The timeout is wired to a shift register that is initialized with "-1" (no timeout). The value from the shift register then crosses the event structure and feeds to the shift register on the right in almost all event cases.
I add two special event cases:
(1) "graph-mouse down" puts a small number (e.g. 10ms) in the right timeout shift register
(2) "graph-mouse up" puts again a -1 in the right timeout shift register
(x) All other event cases (incl. timeout) wire the current timeout straight across to the right shift register.
The timeout event contains the logic to read the graph cursors and associated actions.
This way there is normally infinite timeout. Once the mouse goes down on the graph, the timeout executes at relatively rapid succession until the mouse is raised again. At which point everything quiets down.
LabVIEW Champion . Do more with less code and in less time .

Xy graph cursor blinks

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

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.
Attachments:
gengraph.llb ‏32 KB
XY.JPG ‏170 KB

Why does the graph cursor (snap mode) snap to unvisible curves? How can i change that?

I display several curves in one graph. To get a better overview the user can filter unwanted curves by setting the attibute to unvisible. There is one cursor switched on in the graph with the option "snap to plot". The user can move the cursor and read the coordinates and curvename. Unfortunately the cursor snaps also to the unvisible curves. How can I block that behaviour? The cursor should only jump on the visible curves.

> with the property Cursor.Plot I can set or get the current plot number
> of the cursor, but I cannot prevent the user to move the cursor to an
> unvisible plot. Labview allows the cursor to be moved to a curve witch
> is unvisible in the graph. I want the user only to be allowed to jump
> betwen the visible curves.
>
The graph cursors can be locked to a particular plot or set to snap to
any plot/point on the screen. You cannot see invisible plots, and you
probably can't see black plots on a black background, but the graph
intentionally lets you place cursors there and other users wouldn't be
happy if it changed.
What we will likely add at some point is a way to truly show and hide a
plot. In the meantime, you can also just change w
hat is plotted.
Hidden plots can be removed, no points, and the cursors will not go there.
Greg McKaskle

Bode magnitude graph cursor not following plot

Hi,
I was wondering if anyone would be able to shed some light on a problem that I am having regarding an XY graph cursor.
I have developed a simple VI to determine the characteristics of a low pass filter using a sine wave ramped in frequency and subsequently monitoring the gain of the filter to create a Bode plot.
Through analysis of the Bode plot I would like to determine the cut-off frequency of the low pass filter under test. I have introduced a cursor into the graph and using a property node I hoped to drive the cursor to the -3dB point in the Y axis and output the cursors corresponding X position thereby determining the cut-off frequency of the filter.
However the cursor never seems to follow the plot beyond the first step of the loop. It feels as if there is a break in the plot between the 1st and 2nd iteration of the while loop used to ramp the signal generator.
I've tried to work out why the cursor won't follow the plot to -3dB but so far I am stumped.
Any help or advice that you could provide would be greatly appreciated ! I have provided the attached VI for clarity.
So liberate your minds and give your soul expression. Open up your hearts, I'll sing for you this song. Let the people sing !
Solved!
Go to Solution.
Attachments:
LPF Auto Test.vi ‏109 KB

I have corrected your VI.
First, you needed to put the property node AFTER the while loop, because you need the graph to be done first and then look at the frequency cut off.
Second, in LV, the property nodes are read from top to bottom. So you need to place the cursor at Y = -3 first, and then read the X position.
I attached the corrected vi
Giuliano Franchetto
Student at the l'Ecole Nationale Supérieure des Mines de Saint-Etienne, cycle ISMIN (FRANCE)
Attachments:
LPF Auto Test.vi ‏109 KB

Error 1055 on Graph cursors.

I am using LabView 2010, expanding on one of the example vis for data acquisition. I want to use graph cursors to allow someone to zoom in on a particular part of a graph. To do so, I have been trying to use property nodes. When a graph has more than one cursor, the property nodes seem to access only the highest indexed cursor. So, I tried to apply a property node to a graph with just one cursor. In particular, I tried to access the x-value of the cursor. When I then run the vi, I get error 1055 "Object reference is invalid". I had hoped to construct the property nodes for one cursor, then add another cursor, and attach property nodes to it. There does not seem to be a way to use property nodes to specify which cursor I am accessing. I have tried a property node with two properties: select cursor as an input, and x-value as an output. The "select cursor" property input seem to have no effect at all.
Is there an example vi for programmatically extracting information from graph cursors?
Joe Rudmin
Solved!
Go to Solution.

Joe,
Please take a look at my screen shot as a reference for getting the x position for a cursor on a graph object. I hope this helps.
Right clicking on the graph and hover over create then property node, cursor, cursor position then cursor x. This should create a property node that gives the position of the cursor on the graph. I understand you are trying to use multiple cursors but this will get you started.
Kyle Hartley
RIO Product Support Engineer
National Instruments
Attachments:
cursor position.JPG ‏42 KB

Run-time engine problem in Labview 2009 and Labview 2010

I have a problem with Labview 2009 and Labview 2010. I updated my Labview 2009 into 2010. But it turned out to be a trial one, because i did not have the serial number. So I uninstalled the Labview 2010. however, the funny stuff came over. I cannot use my Labview 2009. So i uninstalled Labview 2009 again. But eventually, I could not reinstall Labview 2009. Every time i had a runtime error and i could not proceed with the installation. in addition, any installation related to Labview is not permitted and the same error came up every time. it is very annoying.
So, What is the deal?
I attached the error here. Any comments or advice are welcomed and appreciated.
Attachments:
error.docx ‏2305 KB

By chance is this machine's language set to any non-English locale? You would check the locale setting by:
Opening Control Panel.
Opening "Regional and Language Options".
Looking Under "Regional Options" >> "Standards and Formats"
If it is set to something besides English, trying setting it to English and please report back what locale it was set to (or if this even solves the problem).
Regards,
- WesW

Distribution problem in labview 2011(Error 11004)

Hi,everyone. I have a problem when i install my build "install". If i include "NI Labview Run-Time Engine 2011" in additional installers, the build files show the error message"
.\Distribution.cpp(2072): InstallerError 11004
Developer Error. Distribution contains invalid dependencies:
1. Product SN1Debug ({4CC67F54-9DD9-4DF2-B9C4-1158C9E9F412}) depends on
product with upgrade code {6AD6C111-233B-4924-A3BF-E4813FE23C7A},
version [11.0.416.0,), language in {}
which is not in the distribution.
Correct the distribution and try again.
<No Debug Message>
" when i install it. and if i don't include it, the install is OK.
I want my distribution include lv2011 run-time engine, how can i do to deal with this problem?
Labview 7.0, 8.0, 8.6,8.6.1,2011
Attachments:
11.png ‏20 KB

Hi,
please try to download and install the NI Labview Run-Time Engine 2011 on your computer and run the builder again.
http://joule.ni.com/nidu/cds/view/p/id/2534/lang/en
In this folder are the installer saved:
C:\Programme\National Instruments\Shared\ProductCache
Regards,
Michael

Graph Cursor Controls

On the graph cursor control (the 4 sectioned diamond that appears withthe cursor legend) I'm wondering what the top and bottom diamond do if anything. The left and right ones are simple enough (forward or back one sample) but the top and bottom ones don't seem to do anything from what I can tell. Are they just for decoration?
Solved!
Go to Solution.

Dan,
I never noticed that before but you're right, in a multi plot graph the up/down diamonds will attach the cursor to a different plot. I never noticed before because I usually change my cursor style so as to not show the horizontal line (just shows the vertical stripe for the cursor).

XY Graph Cursor Problem in Labview 7.1.1?

Similar Messages

Maybe you are looking for