How to switch booleans whithin a loop to 0 when stop is hit

I am trying to write a program than can send digital signal to an external oscilloscope. I am using NI-USB-6008. The program runs but when I hit "STOP" button (while the On/Off signal's boolean switch is on) the oscilloscope still shows an ON signal.
The problem: How to switch the boolean to Off immediately when I press STOP?
I tried using "Clear Task" and "joining the STOP button with the boolean switch but nothing change. Please find attached my program.
Solved!
Go to Solution.
Attachments:
DigOut.vi ‏18 KB

altenbach wrote:
Jeff Bohrer wrote:
since you are looking at error status in the loop conditional logic I would recommend putting a second write outside the loop to garantee the write happens when exiting on error. Additionally, add an error handler after the clear task .
Depending on what the error was, the last write might fail inside or outside the loop, Exactly- and the most compelling reason to add an error handler
so there is no real difference to my suggestion. Except the user is notified of the error and that the hardware may not be in the expected state
You would also need to clear the error before the last write outside else it would not do much anyway..Pssst it was or more correctly the write outside was not passed the error out from the loop and a merge errors is used to pass on the error information
Jeff

Similar Messages

How to use Boolean values from 2 different sources to stop a while loop?

I am working on a program for homework that states E5.4) Using a single Whil eLoop, construct a VI that executes a loop N times or until the user presses a stop button. Be sure to include the Time Delay Exress Vi so the user has time to press the stop botton.
I am doing this right now but it seems as though I can only connect one thing to the stop sign on th while loop. It won't let me connect a comparision of N and the iterations as well as the stop button to the stop sign on the while loop. So how would I be able to structure it so that it stops if it receives a true Boolean value from either of the 2 sources (whichever comes first)?
Basically, I cannot wire the output of the comparison of N and iterations as well as the stop button to the stop button on the whlie loop to end it. Is there a solution?
Thanks!
Solved!
Go to Solution.

Rajster16 wrote:
Using a single Whil eLoop, construct a VI that executes a loop N times or until the user presses a stop button.
Look in the boolean palette for something similar to the word hightlighted in red above.
LabVIEW Champion . Do more with less code and in less time .

How can you automatically disable data on a phone when the user hits the limit?

One Verizon phone rep said she would take care of it for me. Obviously that didn't happen so Verizon robbed me of $50 in overage fees.
Next Verizon store rep told me to go online and do it. Still haven't figured it out. So, anyone know the answer?
Not Thrilled at all with the amount of time I've spent trying to get this accomplished.

That gets trickier, you can install apps to monitor but stopping usage may require FamilyBase from Verizon at an additional monthly cost.
Going over the data limits on your iPhone or iPad? Here's how to track usage and prevent extra fees! | iMore

Dual boot OSX and 9.2, how to switch back to OSX?

Hi Guys,
I am brand new to Mac. I was given this iMac Power Mac 750 600Mhz with 256MB memory and a 80G hard drive. When I got it, it boots to OS X and I don't know what I did (maybe because I plugged in a USB hard drive) but it started to boot to OS 9.2 now, and I don't know how to switch back to OS X.
I remember, when I plugged in the USB flash key, it was running OS X, and it asked me to hold on the power button for several seconds to reboot, I followed that, and it boots to 9.2 ever since.
How do I make it boot to OSX?
Thanks!

Hi Hexar,
First of all, Welcome to the  Discussion forums and to Mac computers!
See: "Mac OS 9, Mac OS X: Press X key during startup to select Mac OS X on single-volume installations"
post back if you have further questions or comments,
LS

How can I repeat a for loop, once it's terms has been fulfilled???

Well.. I've posted 2 different exceptions about this game today, but I managed to fix them all by myself, but now I'm facing another problem, which is NOT an error, but just a regular question.. HOW CAN I REPEAT A FOR LOOP ONCE IT HAS FULFILLED IT'S TERMS OF RUNNING?!
I've been trying many different things, AND, the 'continue' statement too, and I honestly think that what it takes IS a continue statement, BUT I don't know how to use it so that it does what I want it too.. -.-'
Anyway.. Enought chit-chat. I have a nice functional game running that maximum allows 3 apples in the air in the same time.. But now my question is: How can I make it create 3 more appels once the 3 first onces has either been catched or fallen out the screen..?
Here's my COMPLETE sourcecode, so if you know just a little bit of Java you should be able to figure it out, and hopefully you'll be able to tell me what to do now, to make it repeat my for loop:
Main.java:
import java.applet.*;
import java.awt.*;
@SuppressWarnings("serial")
public class Main extends Applet implements Runnable
     private Image buffering_image;
     private Graphics buffering_graphics;
     private int max_apples = 3;
     private int score = 0;
     private GameObject player;
     private GameObject[] apple = new GameObject[max_apples];
     private boolean move_left = false;
     private boolean move_right = false;
    public void init()
        load_content();
        setBackground(Color.BLACK);
     public void run()
          while(true)
               if(move_left)
                    player.player_x -= player.movement_speed;
               else if(move_right)
                    player.player_x += player.movement_speed;
               for(int i = 0; i < max_apples; i++)
                   apple.apple_y += apple[i].falling_speed;
               repaint();
               prevent();
               collision();
          try
          Thread.sleep(20);
          catch(InterruptedException ie)
          System.out.println(ie);
     private void prevent()
          if(player.player_x <= 0)
          player.player_x = 0;
          else if(player.player_x >= 925)
          player.player_x = 925;
     private void load_content()
     MediaTracker media = new MediaTracker(this);
     player = new GameObject(getImage(getCodeBase(), "Sprites/player.gif"));
     media.addImage(player.sprite, 0);
     for(int i = 0; i < max_apples; i++)
     apple[i] = new GameObject(getImage(getCodeBase(), "Sprites/apple.jpg"));
     try
     media.waitForAll();
     catch(Exception e)
          System.out.println(e);
     public boolean collision()
          for(int i = 0; i < max_apples; i++)
          Rectangle apple_rect = new Rectangle(apple[i].apple_x, apple[i].apple_y,
apple[i].sprite.getWidth(this),
apple[i].sprite.getHeight(this));
          Rectangle player_rect = new Rectangle(player.player_x, player.player_y,
player.sprite.getWidth(this),
player.sprite.getHeight(this));
          if(apple_rect.intersects(player_rect))
               if(apple[i].alive)
               score++;
               apple[i].alive = false;
               if(!apple[i].alive)
               apple[i].alive = false;
     return true;
public void update(Graphics g)
if(buffering_image == null)
buffering_image = createImage(getSize().width, getSize().height);
buffering_graphics = buffering_image.getGraphics();
buffering_graphics.setColor(getBackground());
buffering_graphics.fillRect(0, 0, getSize().width, getSize().height);
buffering_graphics.setColor(getForeground());
paint(buffering_graphics);
g.drawImage(buffering_image, 0, 0, this);
public boolean keyDown(Event e, int i)
     i = e.key;
if(i == 1006)
move_left = true;
else if(i == 1007)
     move_right = true;
          return true;
public boolean keyUp(Event e, int i)
     i = e.key;
if(i == 1006)
move_left = false;
else if(i == 1007)
     move_right = false;
return true;
public void paint(Graphics g)
g.drawImage(player.sprite, player.player_x, player.player_y, this);
for(int i = 0; i < max_apples; i++)
     if(apple[i].alive)
          g.drawImage(apple[i].sprite, apple[i].apple_x, apple[i].apple_y, this);
g.setColor(Color.RED);
g.drawString("Score: " + score, 425, 100);
public void start()
Thread thread = new Thread(this);
thread.start();
@SuppressWarnings("deprecation")
     public void stop()
     Thread thread = new Thread(this);
thread.stop();
GameObject.java:import java.awt.*;
import java.util.*;
public class GameObject
public Image sprite;
public Random random = new Random();
public int player_x;
public int player_y;
public int movement_speed = 15;
public int falling_speed;
public int apple_x;
public int apple_y;
public boolean alive;
public GameObject(Image loaded_image)
     player_x = 425;
     player_y = 725;
     sprite = loaded_image;
     falling_speed = random.nextInt(10) + 1;
     apple_x = random.nextInt(920) + 1;
     apple_y = random.nextInt(100) + 1;
     alive = true;
And now all I need is you to answer my question! =)

package forums;
import java.util.Random;
import javax.swing.Timer;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
public class VimsiesRetardedAppleGamePanel extends JPanel implements KeyListener
private static final long serialVersionUID = 1L;
private static final int WIDTH = 800;
private static final int HEIGHT = 600;
private static final int MAX_APPLES = 3;
private static final Random RANDOM = new Random();
private int score = 0;
private Player player;
private Apple[] apples = new Apple[MAX_APPLES];
private boolean moveLeft = false;
private boolean moveRight = false;
abstract class Sprite
    public final Image image;
    public int x;
    public int y;
    public boolean isAlive = true;
    public Sprite(String imageFilename, int x, int y) {
      try {
        this.image = ImageIO.read(new File(imageFilename));
      } catch (IOException e) {
        e.printStackTrace();
        throw new RuntimeException("Bailing out: Can't load images!");
      this.x = x;
      this.y = y;
      this.isAlive = true;
    public Rectangle getRectangle() {
      return new Rectangle(x, y, image.getWidth(null), image.getHeight(null));
class Player extends Sprite
    public static final int SPEED = 15;
    public Player() {
      super("C:/Java/home/src/images/player.jpg", WIDTH/2, 0);
      y = HEIGHT-image.getHeight(null)-30;
class Apple extends Sprite
    public int fallingSpeed;
    public Apple() {
      super("C:/Java/home/src/images/apple.jpg", 0, 0);
      reset();
    public void reset() {
      this.x = RANDOM.nextInt(WIDTH-image.getWidth(null));
      this.y = RANDOM.nextInt(300);
      this.fallingSpeed = RANDOM.nextInt(8) + 3;
      this.isAlive = true;
private final Timer timer = new Timer(200,
    new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        repaint();
public VimsiesRetardedAppleGamePanel() {
    this.player = new Player();
    for(int i=0; i<MAX_APPLES; i++) {
      apples[i] = new Apple();
    setBackground(Color.BLACK);
    setFocusable(true); // required to generate key listener events.
    addKeyListener(this);
    timer.setInitialDelay(1000);
    timer.start();
public void keyPressed(KeyEvent e) {
    if (e.getKeyCode() == e.VK_LEFT) {
      moveLeft = true;
      moveRight = false;
    } else if (e.getKeyCode() == e.VK_RIGHT) {
      moveRight = true;
      moveLeft = false;
public void keyReleased(KeyEvent e) {
    moveRight = false;
    moveLeft = false;
public void keyTyped(KeyEvent e) {
    // do nothing
public void paintComponent(Graphics g) {
    super.paintComponent(g);
    //System.err.println("DEBUG: moveLeft="+moveLeft+", moveRight="+moveRight);
    if ( moveLeft ) {
      player.x -= player.SPEED;
      if (player.x < 0) {
        player.x = 0;
    } else if ( moveRight ) {
      player.x += player.SPEED;
      if (player.x > getWidth()) {
        player.x = getWidth();
    //System.err.println("DEBUG: player.x="+player.x);
    Rectangle playerRect = player.getRectangle();
    for ( Apple apple : apples ) {
      apple.y += apple.fallingSpeed;
      Rectangle appleRect = apple.getRectangle();
      if ( appleRect.intersects(playerRect) ) {
        if ( apple.isAlive ) {
          score++;
          apple.isAlive = false;
    g.drawImage(player.image, player.x, player.y, this);
    for( Apple apple : apples ) {
      if ( apple.isAlive ) {
        g.drawImage(apple.image, apple.x, apple.y, this);
    g.setColor(Color.RED);
    g.drawString("Score: " + score, WIDTH/2-30, 10);
private static void createAndShowGUI() {
    JFrame frame = new JFrame("Vimsies Retarded Apple Game");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(new VimsiesRetardedAppleGamePanel());
    frame.pack();
    frame.setSize(WIDTH, HEIGHT);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
public static void main(String[] args) {
    SwingUtilities.invokeLater(
      new Runnable() {
        public void run() {
          createAndShowGUI();
}Hey Vimsie, try resetting a dead apple and see what happens.

How do I run two while loops independent of each other?

I have a simple VI. I have loop 1 with and LED and a stop button and I have loop 2 with an LED and stop button. They are both in while loops. When I run the VI,if I stop loop 1, I can not turn it back on. If I stop loop 2, it will not stop. I've attached a file with my VI.
Attachments:
2 Loops.vi ‏9 KB

bebesbabe,
This looks like a learning exercise, so I will not present a complete solution.
1. It is not polite to post to the Forum a VI which will not stop except by pressing the Abort button. The Abort button should only be used to stop a VI if something is wrong with the program during development. Add a stop button to the outer loop.
2. A loop with no delay will try to run as fast as possible, consuming all the CPU resources it can get. Since these loops are for user interfaces, delays of 100 to 200 ms are appropriate. Use the Wait (ms) function.
3. Your main problem is understanding dataflow. In LabVIEW any node may execute only when all of its inputs have been given data and it will not complete its execution until all nodes inside it have completed. Your VI does not have external inputs so waiting for data is not a factor. Each loop is considered a node. So the outer loop will iterate only after BOTH of the inner loops have stopped. On the next iteration both inner loops will be started again. Of course if the stop buttons are still pressed, the will stop after one iteration, which will seem almost instantaneous. But because of dataflow as I have described, your program cannot really work the way you want. You cannot restart one loop until both have stopped. Put an indicator on the "i" terminal of the outer loop.
4. You may wish to consider changing the mechanical action on your stop buttons to Latch when Released. Read the help to learn about mechanical actions.
The way the instructions on the front panel read, it is not clear what the intended solution is. What control or user action or program action is required to turn the loops back on? Changing the stop button? Automatically after a delay? A separate On switch? How is the entire program supposed to stop?
Lynn

AS: how to switch between screen modes?

hi @ all,
does anybody know how to switch between the 4 screen modes in ps cs3?
- standard
- maximized
- full screen with menubar
- full screen
I looked around but could not find anything discribing a way doing this by applescript.
the only thread I found
http://www.adobeforums.com/webx/.3bc85cba/0
refers to javascript but I was not able to adopt it.
thanks for any help
Claus

To do it with AS only, you need to simulate the "f" key with System Events:
tell application "System Events"
tell process "Adobe Photoshop CS3" to keystroke "f"
end tell
That will loop thought the screen modes as if you did it manually.
To run the JS from the other thread, you need to use the "do javascript" command. Remember to escape all the quotes in the JS:
tell application "Adobe Photoshop CS3"
do javascript "var screenModeOptions = new Array(4);
     screenModeOptions[0] = \"screenModeStandard\";
     screenModeOptions[1] = \"screenModeMaximized\";
     screenModeOptions[2] = \"screenModeFullScreenWithMenubar\";
     screenModeOptions[3] = \"screenModeFullScreen\";
     applyScreenMode(screenModeOptions[0]);
     function applyScreenMode(mode){
      var desc = new ActionDescriptor();
      var ref = new ActionReference();
      var menuID = stringIDToTypeID( mode );
      ref.putEnumerated( charIDToTypeID( \"Mn \" ), charIDToTypeID( \"MnIt\" ), menuID );
      desc.putReference( charIDToTypeID( \"null\" ), ref) ;
      executeAction( charIDToTypeID( \"slct\" ), desc, DialogModes.NO );
end tell
The JS is the better solution if you wanted to skip directly to the desired screen mode without looping through the others.
Carl.

How to implement boolean control via network

Hi,
I am developing an application by using LabVIEW 8.2 and RealTime. There is a host PC connecting to a PXI
through network cable. Application VIs are running at PXI and GUi is running at host PC. My problem is
When I config a boolean control as "Latch when release" mechanism, pass it to a shared network variable
and then to a boolean control at PXI. "Latch when release" mechanism seems not run very well. Most of the
time, no action when I press the boolean control button in my GUI. It seems that shared network variable
could not act as "Latch when release" mechanism. I checked some examples from NI. Most of examples set
the boolean control button mechanism as "Switch when press" and manually switch it status later on. I have
a bunch of such boolean control buttons in my GUI. It will be hard to handle every of them in this way.
I'd like to know whether there is an easier solution for this.
Thanks
Jason

Hi Jason,
How are you passing the shared variable to the Boolean control in PXI VI?
Here is something to try out.
--Configure the Boolean controls on both systems to "latch until released".
--Create the shared variable (network-published) on the host PC and wire the output of the Boolean control to it.
--On the remote system, bind the Boolean control to the shared variable on the host PC. To bind to the shared variable, right click the Boolean control
   and select properties. Then select the "Data Binding" tab in the property window. Set the "data Binding selection" option to "Shared Variable Engine
   (NI-PSP)" and browse for the path to the shared variable created on the host PC.
--With this setting, whenever the Boolean control on the remote system (PXI) reads a true value, it stays true until the value is read by LabVIEW and
    goes back to the initial (false) state.
Checkout the attached sample LabVIEW project.
Tun
Message Edited by Tunde A on 12-12-2006 05:27 PM
Attachments:
Boolean Shared Var.zip ‏18 KB

Sharing booleans across while loops

I am new to Labview and I am attempting to use an angular encoder as a type of switch.
I want to take continuous measurements of the encoder angle and turn on an analog output signal whenever a certain angle is reached. When the encoder drops below that angle, I need the signal to be turned off.
To do this I am attempting to run two parallel while loops. One measures the angle of the encoder while the second creates the output signal. What I want to do is put a logical statement in the measuring loop that will register 'true' if the maximum angle is reached. I am attempting to pass this 'true' statement to the signal generation loop as a kind of trigger to turn on (using an case structure and 'DAQmx Start Task.vi') the output. The issue I am having is that the 'true' statement can't leave the measuring loop until the loop is complete. But since I am running this continuously, the loop never ends. Thanks.
Solved!
Go to Solution.

Create a local variable of the boolean in concern. Right click on the local and select Change to Read. Put this local inside the other loop. So you have one loop that writes to the boolean and one loop that reads from the local. Now you can remove the wire that comes from one loop and feeds the other. Then your loops will run in parallel (if there are no other data dependencies between the two loops).
As alternatives to local variables, you can use a queue to pass data from one loop to another. One loop (the producer) will write to the queue. The other loop (the consumer) will read from the queue. See examples on Producer-Consumer architecture for more info.
- tbob
Inventor of the WORM Global

How to switch off automatic creation of the business partner?

Hello!
Advise please why in erp after creation of the customer automatically form business partner? How to switch off automatic creation of the business partner? It very much disturbs, because business partner are created from crm. Because of automatic creation business partners are duplicated.

Hi,
I have made the following customizing settings to activate customer integration with business partner, but the problem is when I create a BP with a role (FI-Customer) the customer is not created automatically.
1. Set BP Role Category for Direction BP to Customer
Roles: FLCU00 - Business Partner FI Customer (FS: BP)
FLCU01 - Business Partner Customer (FS: BP)
2. Defined the Number assignment for Direction BP to customer
4. Customer account group and numbering is also defined.
3. Created a BP with BP Role FLCU00, I can see the Customer - General Data tab, but no customer was automatically generated by the system.
Kindly let me know if any customizing I have missed.
Regards
Ameya

Working in Logic 9, how do I use a drum loop WITH ITS PRESET EFFECTS? I can drag and drop the loop but it plays dry in timeline. thanks

Working in Logic 9, how do I use a drum loop WITH ITS PRESET EFFECTS? I can drag and drop the loop but it plays dry in timeline. thanks

Here's the short-cut solution:
Green Apple tracks are MIDI files (so to speak). If you drag one from the loop browser (Capitol C Orchestral hit, as you mentioned in this exable) directly into the arrange page it creates the MIDI file and the instrument to play it back on.
HOWEVER.If you create and audio track first, THEN drag the green Apple loop onto that track, the loop will get "bounced" with the reverb in tact and you'll have the exact sound that you heard in the preview.
Make sense?

How can I get my ES2 loops to play correctly? I keep getting the message that the audio is not found when I drag the loops from my audio browser even though they play fine in the preview.

How can I get my ES2 loops to play correctly? I keep getting the message that the audio is not found when I drag the loops from my audio browser even though they play fine in the preview.

It's exactly as I stated. Whenever I try to drag these kinds of loops (ESX24 / software instrument loops? the ones marked in green with the white music note next to them) from the loop browser into the timeline a message comes up saying Audio Not Found for that loop. And a new track is created automatically when loops are dragged into the timeline, so I'm not creating some other random / synth instrument track so I'm not sure what the deal is... But perhaps I'll try creating a software instrument track first and then drag the loop into that track and see what happens - maybe there's something with the default settings that automatically creates audio tracks whenever loops are imported?

How to out from infinite while loop in sub VI

Dear Sir,
how to out from infinite while loop in sub VI from main VI
attached photo for solution but I can't understand it and i can't find the function in photo
please help
Attachments:
stop_subVI_frm_main.JPG ‏36 KB

Asking how to get out of an infinite loop is like asking how to find the end of a circle. I'm not trying to be sarcastic but by definition, if there is a way out of the loop, then it is not infinite. I think what you are asking is how to avoid creating an infinite loop. Is there something about the suggestions you have been given that you do not like? My favorite suggestion is the notifier but maybe you just need an example. Turn on context help and read about the notifier functions in the code below.
This is your top level VI
And this is your subVI
If this seems too complex then a global variable will work too. But what seems simpler can cause much more complex bugs. You can code fast and spend lots of time debugging or you can code slow and spend less time debugging. Personally I perfer writing productive code than looking for bugs any time.
=====================
LabVIEW 2012

How to write Boolean function (If Then Else)?

Hi all,
I have a logic to write in the query. It is:
If (A = 0 and B = 0)
Then 0
Else
        If (A = 0 and B > 0)
        Then 100
        Else
               A/B (we want to show %)
How to use boolean function to write this Netted If Else statement? Thank you in advance!

Hi
If (A = 0 and B = 0)
Then 0
Else
If (A = 0 and B > 0)
Then 100
Else
A/B (we want to show %)
1. create a formula in the query designer. and use this formula for if - else
( ( (A==0) AND (B==0) ) * 0) + ( ( a==0 ) AND (B >0 ) * 100 + (A/B*100) )
: denotes THEN
+ : denotes ELSE
See if this works.
Assign points if helpfull
From
ManesH

How can I watch movies in germany with native tone, english? Any one knows how to switch the language when renting a movie?

How can I watch movies in germany with native tone, english? Any one knows how to switch the language when renting a movie?

I wonder the Format Tables macros on my site could be adapted?
http://www.grainge.org/pages/authoring/word/word_macros.htm
If not, I have used Macro Express to format tables in Rh. No reason it could not be used in Word.
See www.grainge.org for RoboHelp and Authoring tips
@petergrainge

How to switch booleans whithin a loop to 0 when stop is hit

Similar Messages

Maybe you are looking for