Howto clear a chart in running programm?

My Program periodically sends data in form of an array to a waveform chart
to display the data.
I want the newer data to overwrite the older, so that always only the last
array of data is displayed.
Therefore I have to clear the actual chart, otherwise LabView puts the data
in row behind each other.
How can I do this?
I found no proper property in the property node that could help me.
Or are there other possibilities?
Thx for help,
Daniel

You wire an empty array to the chart history property node. Look at the shipping example called "How to Clear Charts & Graphs".

Similar Messages

Why is the first value missing in the Chart when I use Property Nodes to clear my Charts programatically ?

Hello everybody,
I am using Property Nodes to clear my Charts right at the beginning of the program. The Property Nodes (History) are outside a While-loop.
When I connect a Chart with the counter-variable "i" inside a While-loop, the first point I see in the Chart is (0,1) instead of (0,0). It looks like the Chart misses the first point !
If the Chart is outside the While-loop the Chart displays all points.
Can anyone please explain this behaviour ? How can I solve this problem ?
Thanks,
Cesar

Make sure you have the error output from the property node connected to
the loop border. Even if the error os not used in the loop, this will
ensure that the property node clears the chart before the loop starts
running.
What is probably happening is the loop start running at the same time
the chart is being cleared, so the first point is also being cleared.
Ed
Message Edited by Ed Dickens on 04-11-2006 09:50 AM
Ed Dickens - Certified LabVIEW Architect - DISTek Integration, Inc. - NI Certified Alliance Partner
Using the Abort button to stop your VI is like using a tree to stop your car. It works, but there may be consequences.
Attachments:
Clear chart before loop.gif ‏4 KB

How to use the "Clear PDA Chart .vi" in LabVIEW 7.1 PDA module?

In my iPAQ application, I try to use the LabVIEW 7.1 PDA module's "Clear PDA Chart .vi" to clear the graph. But I do not know how to do it. I always get error when I call it.
My code is attached. The code is to draw a sin wave and then clear it.
Attachments:
sin.vi ‏69 KB

Hi,
I verified the behavior that you reported. I got error code 260055065 on running the VI. It does not matter if you wire a control ref or tabbing order number to the Clear PDA Chart.vi.
This is a known bug and LabVIEW PDA developers are already working on it. Hopefully it will be fixed in the next release of the PDA module. Thanks for bringing this to our attention.
Regards,
Ankita A.
National Instruments

How can I programmatically clear a chart?

Hi,
Could you please let me know how can I programmatically clear a chart? I would like to run a code multiple times and everytime I run it , the chart should be cleared . I tried to find a History property node but seems like there is no such properfy node for chart

If I have conceived your problem clearly, there is of course history data property node for charts. You may get one by right clicking on chart
create>>Property node>>History data(which is last on list)
CLAD
Passionate for LabVIEW

How do you set the size / bounds of a waveform chart at run time?

I have a plot area that I would like to fill with as many waveform charts as the user specifies (at run time). The "bounds" property is read only and I haven't noticed an additional "size" property for a waveform chart as there is for a button. Is there a way to set the size of a waveform chart at run time, and if not, why not? (Labview 6.1)

Look at it a little more carefully, I suspect that your assumption is only half wrong. The property does only resize the plot area--LV resizes the frame to fit the resized plot on it's own.
You'll need to bear this in mind when you're figuring-out what size to set the property to.
Mike...
Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion
"... after all, He's not a tame lion..."
Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

Import new java classes into a running programm

Hello, i have a small Java problem, i hope somebody knows an answer ...
I try to write a Java Programm, this programm starts and load a new class, this class is not defined inside the running programm, but the running programm should use the new class.
example:
// a class file in a directory somewhere at my harddisk
public void class X
void doSomething()
//Print "Hello world"
start programm A
Programm A does something, but doesn�t "know" class X, class X is not compiled with program A
after some seconds, A should load class X.
if (M == N) "import class X"
// At this moment, Programm A knows class X
X NewObjektX = new X();
NewObjektX.doSometing();
Thats my problem :)
I am sorry about my bad english, but its sadly not my first language.

Hello :)
Thx for an answer, i tried your solution, but i get another problem.
The type to create an object ist unknown.
i?ll post my exmaple code :
This class is not compiled with the main programm, only the class file is inside the directory of the main program.
public class SimpleClass
     int Information = 0;
     void printOnScreen()
         System.out.println("Varibale of the class:"
           + this.Information);
This is the main programm:
public class Main {
     public static void main(String[] args)
          try
            Class newClass = Class.forName("SimpleClass");
            Object instance = newClass.newInstance();
              System.out.println(instance.getClass());
              // At this point no errors, the tpye of instance is
                 "SimpleClass"
              // This line occurs an error, the type "SimpleClass" is
              // unknown.
            SimpleClass newClassInstance = (SimpleClass) instance;
          catch (ClassNotFoundException e)
            System.out.println("Can?t open Class");
            System.err.println(e.getMessage());
          catch (InstantiationException e)
           System.out.println("Error1");
           System.err.println(e.getMessage());
          catch (IllegalAccessException e)
             System.out.println("Error2");
           System.err.println(e.getMessage());
      } // public static void main(String[] args)
} // public class MainI tried another solution with inheritance, i programmed a superclass, and choose the superclass as the type (the Superclass was compiled with the main programm).
The SimpleClass extends Superclass.
// works fine, but i dont want this type of solution :)
Superclass newClassInstance = (Superclass) instance;
How cann i solve the "unknown type" problem ?
SimpleClass newClassInstance = (SimpleClass) instance;

How to clear waveform chart

How i can clear a waveform chart with dynamic datas? The normal procedure with handover a empty array doesnt work.
Uwe Augst
Muehlbauer AG
Germany

Hi,
here´s a small example with a property node (Historie), everytime you restart that VI, first the chart is cleaned up and than refilled again.
Hope this helps,
AlexMessage Edited by Alex R on 05-03-2005 11:18 AM
Attachments:
Clear Waveform-Chart.vi ‏21 KB

Clear shift registers between runs

Hi,
Noob question of the day! I am building an array and would like to clear shift registers between runs. I have attached a VI. It runs a while loop every second and adds that iteration number to an array. I then display the length of the array. I would like it such that each time I press run, the program starts with a "blank slate." Any standard way of clearing everything. I would love to do something like:
clc
clear
if it were matlab...
Solved!
Go to Solution.
Attachments:
shift register count.vi ‏8 KB

What do you know, I guess the problem is that I am left handed. Sometime I even confuse up and down.
Yes I meant the right-click the left shift register.
LabVIEW Champion . Do more with less code and in less time .

Access 2010 Charts - Query runs but Chart displays black screen

Hi,
I developed a db in MS Access 2007 on my old PC and everything worked perfectly. After trying to open it on my new PC using Access 2010 the db works except the charts display as a black area.
After a bit of playing around I can say for certain that the queries for the charts are running correctly, (and of course the colouring of the chart is correct).
I tried deleting the charts but I got an error message saying "cant find the OLE library".
As I'm relatively new to creating exe files for transferring db's I'm thinking I need to bring the ole library with the db?? but I cant seem to find it on my old pc (maybe being stupid)
Please could you tell me if I'm barking up the wrong tree with this, or if there is a simple fix that I'm overlooking?
Many thanks
Tom.

I was having this exact same problem, then it just stopped. I am using the nouveau driver and I have a tnt2 card.
IIRC, I was having an unrelated problem with xorg or udev or something was having problems detecting my monitor, it claimed I had two monitors connected, I wrote an xorg.conf file and that fixed the problem. IDK if its is related or not because I don't recall exactly when things started working when I would switch ttys.
Try using the nouveau driver and see if it does the same thing, it has a kernel module so it might make difference,
Last edited by RiceKills (2010-07-06 23:39:27)

How to programmatically clear the chart

Good morning
I have doubt in clearing a chart programmatically
I need to display the the values in chart and clear the chart,again i need to display in the next cycle
I am able to display values and clear programmatically(passing some empty array values), but not able to diplay values in next cycle
Pls give me some suggestions

If i want clear the chart only after the time scale reached 100, how can i do this
Consider changing the ADVANCED - UPDATE MODE to SCOPE chart.
That will clear automatically when your data gets to the right side, and start over.
Otherwise, clear it anytime you like by sending an empty array of points to your chart's HISTORY DATA property.
Steve Bird
Culverson Software - Elegant software that is a pleasure to use.
Culverson.com
Blog for (mostly LabVIEW) programmers: Tips And Tricks

Clearing a chart?

Hi!
Is there a way to clear a chart from a VI rather than
through direct user interaction with the chart?
Rudolf

Nevermind ... it's in the help ... wire an empty array
to the historydata attribute.
Rudolf Potucek wrote:
: Hi!
: Is there a way to clear a chart from a VI rather than
: through direct user interaction with the chart?
: Rudolf

How do I clear the data in a waveform chart before running the vi?

I'm sending data via TCP and I want to have the chart displaying the sent data clear itself when I start the VI. How can I do this?

you can use the History Data property and wire an empty array to it...
(right click the control --> Create --> Property Node --> History Data)
Dan

How to create a subVI to Clear all charts data on a main VI

Hi all,
As I am writing a subVI to clear all the "charts" data on a main VI.
The number of Charts is unknown, beasue this subVI need to run at
difference main VIs. Therefore, I can only input a ref. of main VI into
the subVI and find out all the control ref.,then check the classes of
the control. If it is a chart, I need to use "To More Specific Class" to
to select waveform chart. However, if the property node is not create
from the chart directly, the "histroy data" will be missing.
No matter my concept to build this subVI should be right, I donot succeed.
Are there any other methods to do that?
regards,
Ryan

parthabe wrote:
Did you file a bug report with NI, Coq?
No i did not. I got it working with some diagram cluttering, and forgot all about it. As my motto is "If the damn thing works, ship it"
Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)

How do you clear the chart in an AI Waveform Scan VI upon program start?

I am using a waveform scan vi in a program. The output of the vi is set to "Waveform". What I want to do is have the program automaticly clear the waveform chart each time the program starts. Currently I must start the program, right click on the chart and select clear. I have attempted to use the chart history property node, which I assumed is the correct path to take but so far my attempts have been unsuccessful.

Ahhh, waveforms... These got better in LV 7 I hear.
Will this do it?
2006 Ultimate LabVIEW G-eek.
Attachments:
Problem_example.vi ‏41 KB

Only first plot of waveform chart has run-time menu

Hello again all you helpful forum-goers!
My multi-plot waveform chart is working decently well, but now for some reason only the first plot in the plot legend displays a run-time customization menu when I click on it while the VI is running (allowing me to select the plot color, etc.). All the other plots do nothing when I click on them. I do not have any mouse-down events or filter events of any kind in my VI. I programmatically set the number of plots and the size of the plot legend, along with each plot's name, y index, and color. Any ideas as to what might be going on?
Thanks a bunch as always!
-Joe
Solved!
Go to Solution.

Okay, hopefully this will help get some more thoughts / answers flowing. I've copied my strip chart from my actual VI into a test VI, and it still exhibits the problem. On the other hand, I have created a new strip chart from scratch, and it works fine. I have attached both VIs here for you to see. My guess is that some property of the first chart is set incorrectly or something, but I cannot figure out which one (and there are so many!).
Any assistance you can give would be appreciated. The challenge is to get the chart in the first VI working (plots other than the first responding to a mouse click to change their color or other attributes), via changing some attribute of the chart (and being able to tell me which one you changed!).
Thank you again for anyone who can look into this.
-Joe
Attachments:
Test StripChart color selection not working.vi ‏17 KB
Test StripChart color selection working.vi ‏12 KB

Howto clear a chart in running programm?

Similar Messages

Maybe you are looking for