Iterate while loop on command

This seems like it should be a relatively simple application of a while loop, but I can't seem to find the solution :/ Basically I have a string control on my front panel for a filename (minus path/extension), and when I start up the VI I check if the file already exists. If it does, I'd like to start a while-loop in which each subsequent iteration only occurs when the string control is changed by the user.
The way I have it wired up now works fine (see attached), but it loops every 50 ms even while there's an invalid string. If possible I'd like to pass to the next iteration only after the control value has changed. This way I can display an error dialog of some sort that won't pop up every 50 ms. (Note: this is a piece of code from a subVI, hence the refnums and property nodes.)
Thank you!
Attachments:
input_loop.vi ‏12 KB

phogan wrote:
The reason for all the refnums is that I'm trying to check controls that are on the main front panel while I'm within this subVI loop. If you have a better idea than that, feel free to let me know. As far as I know references are the only way to access a control that may be changing once you've already entered a subVI.
Thanks for the tip on the event structure, I'll give that a shot tomorrow.
Yes, refs are the only way to control front panel objects from another vi, but do you need to? Send the value to the checking vi and react to that, if need be return a Valid boolean or similar, that's how it's usually done.
/Y
LabVIEW 8.2 - 2014
"Only dead fish swim downstream" - "My life for Kudos!" - "Dumb people repeat old mistakes - smart ones create new ones."
G# - Free award winning reference based OOP for LV

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Making a Menu in the command console w/ a While loop

Hello,
I need to design a menu in the command console that allows the user to enter a choice, and after doing so will bring the user back to the original menu of options.
Now I already have set up the menu and I got it working so the user can enter their choice however my questions is, I know I need to use a while loop, but how would I go about doing so in order to have it set up that after a choice is entered it displays the results and then goes back up to the original menu.
I know these new versions of Java do not have a simple GOTO command I can use so I was told a while loop is the way to do it. I know how to set up while loops, I guess what I am asking is what my terminating/repeating condition should be and how to get the program to go back up to the top of the loop thus displaying the menu. Is there any way to maybe use a return false/true and have the loop keep going through only if true? Thanks in advance.

while( condition )
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While loop not performing correctly

When I enter ANY number, the second while loop in the code below executes. It should not execute when 117, 239, 298, 326, or 445 is entered. I can't seem to figure out why this does not work, and I do not know what else to try.
Hope someone can just give some assistance. Thank you!
If I need to supply the entire program, just let me know.
while(! done)
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JosAH wrote:
paulcw wrote:
The outer loop loops on "not done", but in the body of that loop, done is unconditionally set to true. So the outer loop will only run once. Therefore it's pointless. I'm guessing that you meant to only set done to true if the user inputs "quit" or something.The 'not done' loop will iterate again if the user supplied incorrect input (not an int).Man that's a confusing flow of control. So if the user types in anything other than a number, it's causes a parse error (basically) and the exception causes it to skip the command to stop, and that makes it loop again.
So apparently 3/4 of the people looking at that code didn't get it at first.
It reminds me of the veda about Mel.
Come up with something clearer.

Accessing Data within while loops

I have LabView 6.0
I have a while loop for my GUI that accesses various sub VIs. One of the Sub VI is a LED on/off thing, which basically checks the communication with the PIC board that I have. For turning the LED on or off, I have to sent a unique command.
Since the Sub VI for the LED on/off is inside a while loop it continuously executes. I want the SubVI to execute only when the status of the boolean controlling the LED has changed from the previous value. I tried giving a feedback from the SubVI to indicate whether there is a change, but Labview will not allow such loops.
I then took the SubVI outside the while loop, keeping the boolean control (so that it continuously checks) inside the while loop. I would like the SubVI to execute depending on the boolean control change. I tried using occurances, but I think these execute only once. I tried accessing the boolean control through a local variable, but the value of the local variable would not change outside of the while loop. (even tried property indicators).
Any solution would be appreciated.
I could post the VI, but there are too many sub VIs... Dunno if it would be appreciated.
Thanks!

If you need to post a VI, it is best to strip out those parts which do not have any effect on the problem you are facing. With subVIs, do a Save with Options..>>Development Distribution. This will create an .llb file with your VI and subVIs.
Queues and global variables can transfer data between independent nodes. I am not sure when the datatypes of queues changed. In LV6 you may need to flatten your data to string typpe before passing it to a queue. The functional global or LV2 style global is a subVI consisting of a loop which executes only once and which contains the data in an uninitialized shift register. Many threads on this forum have discussed these options.
Lynn

How can i get the while loop to enter a different loop beside the first one

I can't seem to figure out how to change the value to enter into one of the other while statements in the script. I am new to this and can't seem to find anything how to enter in the information to be able to go to different while statements and then run
what is located in that statement.
The script is supposed to let me choose between TC, MonsterLock, and Cyc and then jump to the while statement that is associated with one of them and then run what ever is located in that block. All i am getting is a infinite loop and it never sees the other
while loops. I have 3 set up the go along with the first statement but no matter what i type in for them it always looks at the first while statement and stays there.
Can someone please help me with having it do what i stated earlier.
write-host "This script sets up DATABASE Staging"
$ProductionDistro = Read-Host -Prompt "Which production do you `enter code here`want to run?(TC/MonsterLock/Cyc)"
While($ProductionDistro -notmatch "(TC|MonsterLock|Cyc)"){
write-host "You have entered an error" -ForegroundColor Red
write-host "You must type TC or MonsterLock or Cyc"
write-host "you typed $ProductionDistro"
write-host "This script sets up DATABASE Staging"
$ProductionDistro = Read-Host -Prompt "Which production do you `enter code here`want to run?(TC/MonsterLock/Cyc)"
while($ProductionDistro -match $TC) {
write-host "Sets up location you want to run staging"
$ElementDistro = Read-Host -Prompt "Which Element do you want to run? (DATABASE1/DATABASE2/DATABASE3/DATABASE4/ALL)"
While($ElementDistro -notmatch "(DATABASE1|DATABASE2|DATABASE3|DATABASE4|ALL)") {
write-host "you have enterd an error" -ForegroundColor Red
write-host "You must type DATABASE1 or DATABASE2 or DATABASE3 or DATABASE4 or ALL"
write-host "you typed $ElementDistro"
write-host "set location you want to run staging"
$ElementDistro = Read-Host -Prompt "Which Element do you want to run? (DATABASE1/DATABASE2/DATABASE3/DATABASE4/ALL)"
While($PrductionDistro -match $MonsterLock){
write-host "Sets up location you want to run staging"
$ElementDistro = Read-Host -Prompt "Which Element do you want to run? (DATABASE1/DATABASE2/DATABASE3/DATABASE4/ALL)"
While($ElementDistro -notmatch "(DATABASE1|DATABASE2|DATABASE3|DATABASE4|ALL)") {
write-host "you have enterd an error" -ForegroundColor Red
write-host "You must type DATABASE1 or DATABASE2 or DATABASE3 or DATABASE4 or ALL"
write-host "you typed $ElementDistro"
write-host "set location you want to run staging"
$ElementDistro = Read-Host -Prompt "Which Element do you want to run? (DATABASE1/DATABASE2/DATABASE3/DATABASE4/ALL)"
while( $ElementDistro -match $DATABASE1 ){
function Execute-MySqlcommand {param( [string]$Server, #the host of the SQL server
[string]$Database1, #the name of the database
[System.Data.MySqlclient.MySqlcommand]$Command) #the command to execute (name of stored command)
$mysqlConnection = new-object System.Data.MySqlclient.MySqlConnection
$MySqlConnection.ConnectionString = "DROP_VIEW DATABASE.BTXADDR;DROP_VIEW DATABASE.BTXSUPB;CREATE_VIEW DATABASE.BTXADDR FOR DATABASE1.DATABASE1S2.BTXADDR;CREATE_VIEW DATABASE.BTXSUPB FOR DATABASE1.DATABASE1S3.BTXSUPB"
$MySqlConnection.ConnectionString = "TRUNCATE TABLE DATABASE1.DATABASE1S2.BTXADDR;TRUNCATE TABLE DATABASE1.DATABASE1S3.BTXSUPB; INSERT INTO DATABASE1.DATABASE1S3.BTXSUPB SELECT * FROM DATABASE1.DATABASE1S2.BTXSUPB; select count(*) from DATABASE1.DATABASE.BTXADDR; select count(*) from DATABASE1S.DATABASE.BTXADDR; select count(*) from DATABASE1.DATABASE.BTXSURB; select count(*) from DATABASE1S.DATABASE.BTXSUPB;"
$Command.CommandType = 1 # 1 is the 'Text' command type
$Command.Connection = $mysqlConnection
$mysqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$mysqlConnection.Close()
if ($Result -gt 0) {return $True} else {return $False}
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[string]$DATABASE1, #the name of the database
[System.Data.SqlClient.SqlCommand]$Command) #the command to execute (name of stored procedure)
$sqlConnection = New-Object System.Data.SqlClient.SqlConnection
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$Command.Connection = $sqlConnection
$sqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$sqlConnection.Close()
if ($Result -gt 0) {return $TRUE} else {return $FALSE}
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#.Synopsis
# Copies all files and folders in $source folder to $destination folder, but with .copy inserted before the extension if the file already exists
param}($DATABASE0980453.pkg,"d/DATABASE1/code_stg")
# create destination if it's not there ...
#mkdir $destination -force -erroraction SilentlyContinue
foreach($original in ls $source -recurse) {
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if($original.PSIsContainer) {
# mkdir $result -ErrorAction SilentlyContinue
# } else {
copy $original.FullName -destination $result
cd /d/DATABASE1/code_stg
install ../DATABASE0980453.pkg
while($ElementDistro -match $DATABASE2 ) {
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[string]$DataBase2, #the name of the database
[System.Data.MySqlclient.MySqlcommand]$Command) #the command to execute (name of stored command)
$mysqlConnection = new-object System.Data.MySqlclient.MySqlConnection
$MySqlConnection.ConnectionString = "DROP_VIEW DATABASE.BTXADDR;DROP_VIEW DATABASE.BTXSUPB;CREATE_VIEW DATABASE.BTXADDR FOR DATABASE2.DATABASE2MS2.BTXADDR;CREATE_VIEW DATABASE.BTXSUPB FOR DATABASE2.DATABASE2S3.BTXSUPB"
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$Command.CommandType = 1 # 1 is the 'Text' command type
$Command.Connection = $mysqlConnection
$mysqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$mysqlConnection.Close()
if ($Result -gt 0) {return $True} else {return $False}
function Execute-MySQLCommand {param( [string]$Server, #the host name of the SQL server
[string]$DATABASE2, #the name of the database
[System.Data.SqlClient.SqlCommand]$Command) #the command to execute (name of stored procedure)
$sqlConnection = New-Object System.Data.SqlClient.SqlConnection
$sqlConnection.ConnectionString = "DATABASE_CONNECT_STRING=DSN=DATABASE2; Description=DATABASE2; Trusted_Connection=Yes;WSID=Server;DATABASE=DATABASE2;"
$Command.CommandType = 1 # 1 is the 'Text' command type
$Command.Connection = $sqlConnection
$sqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$sqlConnection.Close()
if ($Result -gt 0) {return $TRUE} else {return $FALSE}
function Copy-File {
#.Synopsis
# Copies all files and folders in $source folder to $destination folder, but with .copy inserted before the extension if the file already exists
param}($DATABASE0980453.pkg,"d/DATABASE2/code_stg")
# create destination if it's not there ...
#mkdir $destination -force -erroraction SilentlyContinue
foreach($original in ls $source -recurse) {
$result = $original.FullName.Replace($source,$destination)
while(test-path $result -type leaf){ $result = [IO.Path]::ChangeExtension($result,"copy$([IO.Path]::GetExtension($result))") }
if($original.PSIsContainer) {
# mkdir $result -ErrorAction SilentlyContinue
# } else {
copy $original.FullName -destination $result
cd /d/DATABASE2/code_stg
install ../DATABASE0980453.pkg
While( $ElementDistro -match $DATABASE3 ) {
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[string]$DATABASE3, #the name of the database
[System.Data.MySqlclient.MySqlcommand]$Command) #the command to execute (name of stored command)
$mysqlConnection = new-object System.Data.MySqlclient.MySqlConnection
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$Command.Connection = $mysqlConnection
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$Result = $Command.ExecuteNonQuery()
$mysqlConnection.Close()
if ($Result -gt 0) {return $True} else {return $False}
function Execute-MySQLCommand {param( [string]$Server, #the host name of the SQL server
[string]$DATABASE3, #the name of the database
[System.Data.SqlClient.SqlCommand]$Command) #the command to execute (name of stored procedure)
$sqlConnection = New-Object System.Data.SqlClient.SqlConnection
$sqlConnection.ConnectionString = "DATABASE_CONNECT_STRING=DSN=DATABASE3;Description=DATABASE3;Trusted_Connection=Yes;WSID=Server;DATABASE=DATABASE3;"
$Command.CommandType = 1 # 1 is the 'Text' command type
$Command.Connection = $sqlConnection
$sqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$sqlConnection.Close()
if ($Result -gt 0) {return $TRUE} else {return $FALSE}
cd /d/DATABASE3/code_stg
install ../DATABASE0980453.pkg
function Copy-File {
#.Synopsis
# Copies all files and folders in $source folder to $destination folder, but with .copy inserted before the extension if the file already exists
param}($DATABASE0980453.pkg,"d/DATABASE3/code_stg")
# create destination if it's not there ...
#mkdir $destination -force -erroraction SilentlyContinue
foreach($original in ls $source -recurse) {
$result = $original.FullName.Replace($source,$destination)
while(test-path $result -type leaf){ $result = [IO.Path]::ChangeExtension($result,"copy$([IO.Path]::GetExtension($result))") }
if($original.PSIsContainer) {
# mkdir $result -ErrorAction SilentlyContinue
# } else {
copy $original.FullName -destination $result
While($ElementDistro -match $DATABASE4 ) {
function Execute-MySqlcommand {param( [string]$Server, #the host of the SQL server
[string]$DATABASE4, #the name of the database
[System.Data.MySqlclient.MySqlcommand]$Command) #the command to execute (name of stored command)
$mysqlConnection = new-object System.Data.MySqlclient.MySqlConnection
$MySqlConnection.ConnectionString = "DROP_VIEW DATABASE.BTXADDR;DROP_VIEW DATABASE.BTXSUPB;CREATE_VIEW DATABASE.BTXADDR FOR DATABASE4.DATABASE42.BTXADDR;CREATE_VIEW DATABASE.BTXSUPB FOR DATABASE4.DATABASE4S3.BTXSUPB"
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$Command.Connection = $mysqlConnection
$mysqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$mysqlConnection.Close()
if ($Result -gt 0) {return $True} else {return $False}
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[string]$DATABASE4, #the name of the database
[System.Data.SqlClient.SqlCommand]$Command) #the command to execute (name of stored procedure)
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$Command.CommandType = 1 # 1 is the 'Text' command type
$Command.Connection = $sqlConnection
$sqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$sqlConnection.Close()
if ($Result -gt 0) {return $TRUE} else {return $FALSE}
function Copy-File {
#.Synopsis
# Copies all files and folders in $source folder to $destination folder, but with .copy inserted before the extension if the file already exists
param}($DATABASE0980453.pkg,,"d/DATABASE4/code_stg")
# create destination if it's not there ...
#mkdir $destination -force -erroraction SilentlyContinue
foreach($original in ls $source -recurse) {
$result = $original.FullName.Replace($source,$destination)
while(test-path $result -type leaf){ $result = [IO.Path]::ChangeExtension($result,"copy$([IO.Path]::GetExtension($result))") }
if($original.PSIsContainer) {
# mkdir $result -ErrorAction SilentlyContinue
# } else {
copy $original.FullName -destination $result
cd /d/DATABASE4/code_st
install ../DATABASE0980453.pkg
While($ElementDistro -match $ALL ){
function Execute-MySQLCommand {param( [string]$Server, #the host name of the SQL server
[string]$DATABASE1,$DATABASE2,$DATABASE3,$DATABASE4, #the name of the database
[System.Data.SqlClient.SqlCommand]$Command) #the command to execute (name of stored procedure)
$sqlConnection = New-Object System.Data.SqlClient.SqlConnection
$sqlConnection.ConnectionString = "(DATABASE_CONNECT_STRING=DSN=DATABASE1;Description=DATABASE1;Trusted_Connection=Yes;WSID=Server;DATABASE=DATABASE1;DATASET=DEFAULT;),(DATABASE_CONNECT_STRING=DSN=DATABASE2; Description=DATABASE2; Trusted_Connection=Yes;WSID=Server;DATABASE=DATABASE2;),(DATABASE_CONNECT_STRING=DSN=DATABASE3;Description=DATABASE3;Trusted_Connection=Yes;WSID=Server;DATABASE=DATABASE3;),(DATABASE_CONNECT_STRING=DSN=DATABASE4;Description=DATABASE4;Trusted_Connection=Yes;WSID=Server;DATABASE=TF90PVS;)"
$Command.CommandType = 1 # 1 is the 'Text' command type
$Command.Connection = $sqlConnection
$sqlConnection.Open()
$Result = $Command.ExecuteNonQuery()
$sqlConnection.Close()
if ($Result -gt 0) {return $TRUE} else {return $FALSE}
install ../DATABASE0980453.pkg
While($ProductionDistro -match $Cyc) {
write-host "Sets up location you want to run staging"
$ElementDistro = Read-Host -Prompt "Which Element do you want to run? (DATABASE1/DATABASE2/DATABASE3/DATABASE4/ALL)"
While($ElementDistro -notmatch "(DATABASE1|DATABASE2|DATABASE3|DATABASE4|ALL)") {
write-host "you have enterd an error" -ForgroundColor Red
write-host "You must type DATABASE1 or DATABASE2 or DATABASE3 or DATABASE4 or ALL"
write-host "you typed $ElementDistro"
write-host "set location you want to run staging"
$ElementDistro = Read-Host -Prompt "Which Element do you want to run? (DATABASE1/DATABASE2/DATABASE3/DATABASE4/ALL)"

OK, so you've got a reasonable input loop early on:
write-host "This script sets up DATABASE Staging"
$ProductionDistro = Read-Host -Prompt "Which production do you `enter code here`want to run?(TC/MonsterLock/Cyc)"
While($ProductionDistro -notmatch "^(TC|MonsterLock|Cyc)$"){
write-host "You have entered an error" -ForegroundColor Red
write-host "You must type TC or MonsterLock or Cyc"
write-host "you typed $ProductionDistro"
write-host "This script sets up DATABASE Staging"
$ProductionDistro = Read-Host -Prompt "Which production do you `enter code here`want to run?(TC/MonsterLock/Cyc)"
I've only added two things to that code: a ^ and $ at the beginning and end of your regex pattern. As originally written, it would have successfully matched any string containing TC, MonsterLock or Cyc (such as "bogusTCwhatever", etc).
Now, instead of a bunch of extra While loops based on $ProductionDistro, what you need is some conditionals (either a Switch statement, or some If/ElseIf). For example:
switch ($ProductionDistro)
'TC'
# Do TC Stuff
break
'MonsterLock'
# Do MonsterLock Stuff
break
'Cyc'
# Do Cyc stuff
break

How can I put a time delay between specific events in a while loop?

How can I put a time delay between specific events within the same while loop? I'm already using the "wait" command to control the overall loop iteration speed. But I want to time the individual events as well.

Hi Jesse,
You can use a flat sequence. In each box you can put your individual events and attached wait.
Don't forget to reduce your total loop time of the time you added in the individual sequences.
Doc-Doc
Doc-Doc
http://www.machinevision.ch
http://visionindustrielle.ch
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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

Why the execution time increases with a while loop, but not with "Run continuously" ?

Hi all,
I have a serious time problem that I don't know how to solve because I don't know exactly where it comes from.
I command two RF switches via a DAQ card (NI USB-6008). Only one position at the same time can be selected on each switch. Basically, the VI created for this functionnality (by a co-worker) resets all the DAQ outputs, and then activates the desired ones. It has three inputs, two simp0le string controls, and an array of cluster, which contains the list of all the outputs and some informations to know what is connected (specific to my application).
I use this VI in a complex application, and I get some problems with the execution time, which increased each time I callled the VI, so I made a test VI (TimeTesting.vi) to figure out where the problem came from. In this special VI I record the execution time in a csv file to analyse then with excel.
After several tests, I found that if I run this test VI with the while loop, the execution time increases at each cycle, but if I remove the while loop and use the "Run continuously" funtionnality, the execution time remains the same. In my top level application I have while loops and events, and so the execution time increases too.
Could someone explain me why the execution time increases, and how can I avoid that? I attached my test VI and the necessary subVIs, as well as a picture of a graph which shows the execution time with a while loop and with the "run continuously".
Thanks a lot for your help!
Solved!
Go to Solution.
Attachments:
TimeTesting.zip ‏70 KB
Graph.PNG ‏20 KB

jul7290 wrote:
Thank you very much for your help! I added the "Clear task" vi and now it works properly.
If you are still using the RUn Continuously you should stop. That is meant strictly for debugging. In fact, I can't even tell you the last time I ever used it. If you want your code to repeat you should use loops and control the behavior of the code.
Mark Yedinak
"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

Trouble with while loop, not sure what to put in it in my project

I'm making a class to a simple command line craps game. I must use a while loop to implement craps rules. The rules that i was given are:
if your first roll is a 4, 5, 6, 8, 9, or 10, you roll again until either you get a 7 (you lose) or you get the number from your first roll. (i thought 7 or 11 wins, like in the next example)
yeah, thats right, not very good directions. The first directions i had for a different way of doing it using if and else statements were:
The player rolls the two dice.
If the sum of the resulting die values is 7 or 11, the player wins.
If the sum is 2, 3, or 12, the player loses.
If something else is rolled, the player has to roll again to determine the outcome.
If the sum of the second roll is the same as what the player rolled the first time, the player wins. Otherwise the player loses.
(You might get a pair of dice and play a few rounds to try it.)
here's my code that i have so far for my craps class, in the middle section, i have previous code that i used for if else statements, that is what im trying to replace: package games;public class Craps {
private Dice dice1;
private Dice dice2;
private int gamesPlayed;
private int gamesWon;
private boolean lastGameWon;
private boolean gameOver;
private int firstRoll;
private int secondRoll;
public Craps() {
dice1 = new Dice(6);
dice2 = new Dice(6);
gamesPlayed = 0;
gamesWon = 0;
lastGameWon = false;
firstRoll = 1;
secondRoll = 2;
     //returns firstroll
public int getFirstRoll(){
return firstRoll;
     //returns secondroll
public int getSecondRoll(){
return secondRoll;
public int getGamesPlayed(){
return gamesPlayed;
public int getGamesWon(){
return gamesWon;
public boolean lastGameWon(){
return lastGameWon;
     public int nextSum()
     dice1.roll();
     dice2.roll();
     return dice1.getSideUp() + dice2.getSideUp();
public void play()
          firstRoll = nextSum();
if (firstRoll == 7 || firstRoll == 11)
          gameOver = true;
          gamesWon++;
          if (firstRoll == 2 || firstRoll == 3 || firstRoll == 12)
          gameOver = true;
               else{
               gameOver = false;
          while (gameOver == false)
          secondRoll++;
public String toString()
return "games - " + gamesPlayed + ", won - " + gamesWon + ", last game won - " + lastGameWon + " First Roll - " + firstRoll +
", Second Roll - " + secondRoll;
i'm really confused on how to get the while loop will keep starting the game over if it is false, am i using the right approach? Also i have to use a while loop, its for a school project.
thanks.

The code you asked for could be:
package games;
public class Craps {
    private Dice dice1;
    private Dice dice2;
    private int gamesPlayed;
    private int gamesWon;
    private boolean lastGameWon;
    private boolean gameOver;
    private int firstRoll;
    private int secondRoll;
    public Craps()
        dice1 = new Dice(6);
        dice2 = new Dice(6);
        gamesPlayed = 0;
        gamesWon = 0;
        lastGameWon = false;
        firstRoll = 1;
        secondRoll = 2;
     //returns firstroll
    public int getFirstRoll(){
        return firstRoll;
     //returns secondroll
    public int getSecondRoll(){
        return secondRoll;
    public int getGamesPlayed(){
        return gamesPlayed;
    public int getGamesWon(){
        return gamesWon;
    public boolean lastGameWon(){
        return lastGameWon;
    public int nextSum()
        dice1.roll();
        dice2.roll();
        return dice1.getSideUp() + dice2.getSideUp();
    public void play() {
        gamesPlayed++;
        firstRoll = nextSum();
        if (firstRoll == 7 || firstRoll == 11)
            gamesWon++;
            lastGameWon = true;
        else if (firstRoll == 2 || firstRoll == 3 || firstRoll == 12)
            lastGameWon = false;
        else
           secondRoll = nextSum();
           if (firstRoll == secondRoll)
              gamesWon++;
              lastGameWon = true;
           else
              lastGameWon = false;
    public String toString()
        return "games - " + gamesPlayed + ", won - " + gamesWon + ", last game won - " + lastGameWon + " First Roll - " + firstRoll +
                ", Second Roll - " + secondRoll;
}I'm not sure of craps rules, the code above makes a first roll and if game isn't won or lose at once (7 and 11 wins, 2,3 or 12 lose) a second roll is done. If the second roll is equals to the first made then the game is won else the game is lose. Is it right?

Outputting sine wave to motor -- While loop placement?

I'm having trouble creating a basic Labview program to drive a motor with a sine wave. I'd like to output one sine wave at a time to my motor and look at the response to eventually get a Bode plot. I'm using the Sine waveform VI and I've got a PXI-7358 controller card.
I'm having trouble figuring out what goes in the while loop. I'd like to output, for example, a 10Hz sine wave to my motor. But when I create a VI as shown below (& attached), my output waveform frequency is nowhere near my input frequency. When I type 10Hz I get no movement out. At 10.01 Hz input the motor oscillates at a few Hz, and at 10.1Hz input the motor oscillates wildly. I don't think it's a problem with my motor or my PID settings, because even when I eliminate the motor commands altogether (second figure below), I get the same unpredictable relation between the frequency I type in and the Waveform graph.
It seems that the output waveform depends on some sort of difference between the while loop execution rate and the PXI-7358 command generation rate. It seems to me that the Sine Waveform.vi should be outside the while loop, but in that case the Load Position.flx only seems to grab one position. Is there a good way to have direct control over output frequency of the sine wave?
Attachments:
one_axis_move11.vi ‏20 KB
one_axis_move12.vi ‏12 KB

matthewg,
Dennis is right, let’s keep this to one forum since it is the same topic of discussion, and I will address some of the issues with your code there.
Chris_G
Sr Test Engineer
Medtronic, Inc.

Circular linked list while loop

i have a circular linked list and i'd like a while loop to iterate though all of them. my problem is that it always excludes the last node. i know why, it's due to the fact that "current.next != alive" skips it from ever accessing the last node. i can't seem to solve it. note that the last node in the list points to the first node (alive):
               while(current.next != alive )
                    prev = prev == null ? prev = alive : prev;
                    //identify the name with it's matching node
                    if(name.equals(current.name.toLowerCase()))
                         prev.next = current.next;
                         dead = current;
                         current = current.next;
                         dead.next = null;
                         while(dead.next != null)
                              dead = dead.next;
                    else
                         prev = current;
                         current = current.next;
               }

//this class assists the client in managing a game of assassinations. it does so by providing options such as verifying a target's existence, getting the list of dead people, getting the lsit of alive people, and moving people from the alive to dead list
public class AssassinManager
     private AssassinNode alive;
     private AssassinNode alive_tail;
     private AssassinNode dead;
     //pre: must send a string array
     //post: nodes are created
     public AssassinManager(String[] names)
          dead = null;
          alive = new AssassinNode(names[0]);
          AssassinNode current = alive;
          System.out.println(names[0] + " is first, " + names[(names.length-1)] + " is last\n\n");
          for(int i = 1; i < names.length; i++)
               while(current.next != null)
                    current = current.next;
               current.next = new AssassinNode(names);
          alive_tail = current.next = new AssassinNode(names[(names.length - 1)], alive);
     //post: outputs all the people still alive
     public void printKillRing()
          AssassinNode last = null, current = alive;
          while(current.next!= alive)
               System.out.println(current.name + " is stalking " + current.next.name);
               last = current.next;
               current = current.next;
          System.out.println(current.name + " is stalking " + alive.name);
     //post: outputs a list of the dead people
     public void printGraveyard()
          AssassinNode last = null, current = dead;
          while(dead != null)
               System.out.println(current.name + " was killed by " + current.killer);
               last = current.next;
               current = current.next;
     //pre: must send a string name
     //post: will return true/false depending on the input if the name is in the killing ring (alive)
     public boolean killRingContains(String name)
          AssassinNode current = alive;
          name = name.toLowerCase();
          while(current.next!= alive)
               if(name.equals(current.name.toLowerCase()))
                    return true;
               current = current.next;
          return false;
     //pre; must send a string name
     //post: will return true/false if the name is in the graveyard list
     public boolean graveyardContains(String name)
          AssassinNode current = dead;
          name = name.toLowerCase();
          while(dead != null && current.next != null)
               if(name.equals(current.name.toLowerCase()))
                    return true;
               current = current.next;
          return false;
     //post: checks if game is over by seeing if there is more than 1 player
     public boolean gameOver()
          AssassinNode current = alive;
          if(current.next == null)
               return true;
          return false;
     //post: outputs the winner's name
     public String winner()
          AssassinNode current = alive;
          if(current.next == null)
               return alive.name;
          return null;
     //pre: must send a string name that exists is alive
     //post: will remove the user from the alive list and add it to the killed list
     public void kill(String name)
          //check if person exists to remove them from alive list
          if(killRingContains(name.trim()) == true)
               AssassinNode prev = null, current = alive, dead = this.dead;
               name = name.toLowerCase();
               while(current != null)
                    System.out.println(current.name);
                    if(name.equals(current.name.toLowerCase()))
                         prev = prev == null ? alive_tail : prev;
                         prev.next = current.next;
                         //dead = dead == null ? current : dead;
                         //while(dead.next != null)
                              //dead = dead.next;
                         if(prev.next == alive)
                              break;
                         current = prev.next;
                    else
                         if(current.next == alive)
                              break;
                         prev = current;
                         current = current.next;
}Edited by: ixxalnxxi on Apr 27, 2008 12:58 AM

Imaging.s - while loop - preboot bundle

I've noticed that either 11.2 or 11.2.1 has added a while loop to imaging.s
the comments indicate it is to allow multiple activities to take place.
i have a preboot bundle that runs img to lay down some zmg files. nice and simple.
in this new scenario, the preboot script just repeats (never exits).
I've had a look around but i haven't found anything that i'm suppose to change to suit the new regime.
anyone else in this situation ?
currently, i've comment out the while loop in imaging.s to allow execution as we would expect it, but it's not the right answer as it will have to be edited for every update.
in my script should i be attempting to export a result code so that the "export IMGSUCCESS=1;break;" lines can get acitivated ?
Code:
#!/bin/bash
# imaging.s
. /bin/config.s auto
mountFloppyifLS120
# Do imaging in a loop and break out when done.
# This allows advanced script in an auto session to check for more work to do
while [ 1 ]; do
#check for environment variable with command to run
if [ "a0" = "a"${#IMGCMD} ] ; then
/bin/img a
#Return codes for img:
# 0 SUCCESSFUL, but no changes on hard drive(s)
# 1 SUCCESSFUL, new image placed on hard drive(s)
# 2 SUCCESSFUL, proxy had no work to be done
# 4 SUCCESSFUL, advanced script brought down to be run
# 1124 SUCCESSFUL, Third Party Imaging Task
else
if test -f "$IMGCMD" ; then
# if the file is a regular file, assume it is a script and in unix format
/usr/bin/dos2unix $IMGCMD
/bin/chmod +x $IMGCMD
fi
$IMGCMD
fi
RESULT=$?
if [ $RESULT"a" = "0a" ] || [ $RESULT"a" = "1a" ] || [ $RESULT"a" = "2a" ] || [ $RESULT"a" = "1124a" ] ; then
export IMGSUCCESS=1
break;
elif [ $RESULT"a" = "4a" ] ; then
dos2unix /bin/zenAdvancedScript
chmod +x /bin/zenAdvancedScript
. /bin/zenAdvancedScript
mv /bin/zenAdvancedScript /bin/zenAdvancedScript.sav
else
echo ZENworks imaging failed with error:$RESULT.
echo ZENworks imaging failed with error:$RESULT. > /tmp/img.log
break;
fi
done
#always run sidChange. It checks to determine if it will do any work or not
sidChange
if test -f /update/ZUpdate.s ; then
#update to new version of ZEN imaging client
. /bin/update.s
fi
/bin/grub.s auto

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How many while loops in an application is appropriate?

Hi,
I am writing an application that is growing and now I'm about to add the 5th while loop on the root level. So far, I have loops for:
1. Receiving data
2. Transmitting data
3. Processing commands
4. Handling front panel events
5. (about to be added) background timed events
My question is this - is there any "recommended" maximum number of while loops in the base VI or is it purely up to the application? I am wondering if it matters, or if I can simply add loops as needed. Other than combining the transmit and receive data which I don't want to do due to speed, there's not much else to combine.
Any comments?
Thanks,
Jason

Isn't LabVIEW wonderful? It is so easy to write applications that do many things seemingly at the same time in paralell.
I would not worry too much about the number of loops. Make sure that each loop is well behaved and only spins if there is really something to do. A single empty loop without any wait statement can be very taxing for the CPU and hurt responsiveness in all other loops.
As long as the UI is nicely responsive and the CPU is not pegged at 100% you're fine.
LabVIEW Champion . Do more with less code and in less time .

How to start/stop 2 parallel while loops

My question might be simple to answer for experts, but as a Labview beginner would be great to receive your help:
I hav a VI with two parallel while loops. The first loop runs in a tact of 100 ms to aquire voltage, speed and to output a speed setpoint for a motor in the same tact, read from a table.
Finally all values are written to a log-file.
The question: As soon as I run my VI, data logging starts too and my motor runs. How can I implement a button to start all loops parallel, and how can they be parallel be stopped too if I want to stop measurement? Tryed to set a local variable for both stop buttons but it didn´t work.
Thanx to all, Markus
Attachments:
screenshot.JPG ‏74 KB
Measure and log data.vi ‏147 KB

SnowMule wrote:
Starting the two is easy; use the error cluster to enforce dataflow.
Stopping them is a little trickier; the code you have now isn't very expandable so I'd recommend finding a different architecture. A notifier functions like a queue with a size of 1, a queue works well for sending commands/data between loops.
There is one other significant difference between queues and notifiers. A queue can only have one reader. If you have multiple readers of a queue who reads it will be random. A notifier can have multiple listeners. It fact, that is it's purpose.
Mark Yedinak
"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

Start stop while loop with tab control

I want to be able to start and stop a while loop by entering and leaving a tab. I am using an event structure to do so but it doesn't seem elegant or the right way to do this. The only way I was able to get it to kind of work is by unchecking the lock front panel box in the event structure. I have attached a sample vi of what I have so far.
Solved!
Go to Solution.
Attachments:
Loop test.vi ‏16 KB

The problem is that you can't even stop the program by hitting the stop button until you leave the tab, which is not a friendly user interface.
Event structures should just handle basic user events. Any given event case should not take a long time to run. While you are in the diagnostics tab, your code is stuck in that while loop. Although fixing the lock front panel allows you to do other things, the LabVIEW is just queuing up all of those other UI events (like Stop button value change) and can't handle them until the inner while loop stops and allows the outer while loop to iterate again.
You should have a parallel while loop to handle the waveform graph. You can use notifiers or queues or an action engine FGV (see Ben's Action Engine Nugget) to pass the starting or stopping of the waveform graph update to the parallel while loop.

Iterate while loop on command

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