How to stop a while loop structure in the event of a main vi

Similar Questions

• How can I set up a structure of the event that sends text when the user presses the button "Return"?

  I'm new to programming of the Structure of the event.  I am trying a program which causes the content of a control to the string to be processed when the user presses the button back in after typing in the control of the chain.  I think (I hope!) that it is simple, I just can't understand how do.

  Basically, I would take the attached VI and change so that the user can send the value of control 'String In' to the indicator "String Out" either by pressing the 'Return' key or press the button 'send string. '

  Any help would be greatly appreciated.

  This example has nothing to do with the RETURN key specifically.  It fires all simply whenever the value of the control is changed.  If you click outside the text box or on another still controls the value changes and still the event is raised.  This is often the desired so if it works in your application, you good to go.

  You CAN ONLY answer a particular key if you wish.  Set your event to meet 'This VI' > key down.  Then, read the proposal Vcle on the left side of the structure of the event and compare it to the RETURN (for example).  The Boolean result of the comparison gets connected to a structure to deal with your code to run inside.  You can also wire Vcle directly to a case structure and execute different code based on which key was pressed last.

• How to have a while loop inside a structure of matter?

  Hi all

  I would like to know how to control a while loop by using the structure of the case? I would like the person to check if the object has is in its original position or not.

  If this is the case, go...

  The object must then do its job, as mentioned in the while loop... as up and down 10blocks...

  Later, when she returns to its original position, the entire process must stop...

  I checked the forums on this http://forums.ni.com/t5/LabVIEW/How-to-stop-while-loops-inside-a-case-structure/m-p/591259

  It is the closest, I can have... but can someone tell me how to program for this? How logic should be?

  
  

• Code Golf: stop two while loops with guaranteed ratio iteration

  Proposal

  In the vein of the tradition of Perl, I would like to see if there is any interest to solve a few puzzles programming in LabVIEW. Can someone post a problem and define the rules to solve.

  Here's a question for beginning/intermediate to sharpen your "palette".

  Description

  With a user action, how you would stop two while loops such as the relationship between iterations is the still the same? Concrete to view this situation is to take action: both instruments use the same source of synchronization to take measures, but second divides the clock down so that it is a little slower than the first whole factor. For example, if the slower instrument is four times slower, then at the end of the VI, the slower instrument takes 100 measures the fastest instrument took 400.

  Rules

  • You can use vi.lib
  • You cannot include any other subVIs
  • Your solution should pass for loop1 interval as low as 25 ms

  Model (joint in LabVIEW 2009)
  

   

  If people are interested in this, then we will find a way to improve future problems. Please post your suggestions and criticisms, but only if you also post a presentation ;-)

  MacNorth wrote:

  [..]

  If we choose the first suggestions, the VI has yet to recover the data at different speeds. You can dedicate a loop for each instrument to disassociate a jitter and latency introduced by their connectivity or the inner workings. This adds a margin of safety when there is a conflict of thread and the pilot. You can also implement a simple counting as altenbach loop and renounce the multiloop complexity.
  [..]

  It is a very good point. But I wanted to make sure, you should / need to discuss the benefits, but also the disadvantages of the design. Implementation of an application is most often a process of 'special cases '. If a framework/design for a single application model does not necessarily correspond to another application.

  Designs are always strongly according to the requirements and constraints. What gives here designs will result in educational services, of course, but not necessarily as reference models for specific applications.

  Advantage of simple loop:

  • No synchronization between several loops required
  • Can easily implement any whole factor between services (quotent & function remains for a case structure

  Disadvantage of simple loop:

  • Take advantage of the multi core systems (at least not much)
  • Can easily run out of the time constraints (material not "not responding" enough, fast manipulation of data takes too long,...)
  • Code will accumulate within the structures of the case, where the readability could suff

  The advantage of multiple loops:

  • See essentially the disadvantages of single loop (several loops solve those)

  Disadvantage of multiple loops:

  • More complex, especially for the sync switch (not beginner friendly, requires a more/better design)
  • May contain easily questions source such as race conditions and locks

  A little side note:

  Even if the equipment works different acquisition rate, this does not necessarily that the software must use different rates for data extraction. You can use the same model of an hour, but get X times more values for the task faster than the slower running. The 'only' thing to care of are the sizes of buffers and bottlenecks in the data transfer.

  MacNorth wrote:

  [..] The best advice published OR shutter multiple while loops (https://www.google.com/search?q=labview+stop+multiple+while+loops) are laughable (and the 'solution' in my model). [..]

  No, it's not laughable. For many applications, this approach to shutter at the same time several loops running is OK. The constraint: only for simple parallel running loops.

  More complex loops (producer/consumer and similar) with the more complex data relationship ships require more valiant approaches such as queues, declaring events or user.

  My 5 cents only,

  Norbert

• How to manage the structure of the event with two loops

  I have a question about the structure of the user event with 2 buttons?

  key 1: START LOGGING DATA

  key 2: STOP LOGGING DATA

  How do I control my

  structure of the event so that it will work? because now that the loop is save data... I can't stop the loop, when I clicked on buttons.

  

  

  

  super_saiyans wrote:

  the problem with moving it is that I don't have control of the DATA RECORD STARTING?

  Of course, you do.  When you get your press conference button, you say your state machine to move to the State of logging.  You must also make sure that you return to visit the State to wait for the event to check out the events of the stop button.

• Structure of the event with gray and disabled controls

  I'm working on a data acquisition program that uses the structure of the event to manage the graphic user interface.  I have a 'start logging' button that raises an event when the value changes and starts to collect data.  While collecting data, the program disables and gray on all controls on the front panel except the button "stop logging" that ends a while loop with in the event of data logging.  If this event is active only when you press "stop recording."  There are other events that are triggered by a mouse up/down, action others controls disabled on the front panel.  The problem is that, while the program collect data if you click on one controls disabled and gray that has a mouse up/down, event, the program seems to hang and will not push the button ' stop logging.  I don't know if his attempts to run another event, but he continues to logging data, I just can't stop it.  I have to use the Cancel button to stop the program.

  The real problem is that a control, even when disabled and grayed out, can still trigger a mouse to the high-low event - controlled, it true?  Also, what happens if an event is raised during execution, another event my understanding was that a single event can run at a time.

  Thank you

  Doug

  Doug,

  By reading between the lines, here a bit...  Looks like you have your data collection and logging code in the box to Start Logging event.  If so, this is part of the problem.  No other case of event cannot run until this one is over.  Move data collection and the registration code to a parallel loop.  Have this loop to sit in an inactive state until you press the Start Logging button.  Then, in case for the button change send a command via a queue to the loop of logging and out the case of the event.  The event loop is then immediately ready to respond to the next event.

  Generally the code within a case of event should run quickly, no more than 10s of milliseconds for maybe 100 ms to avoid slow response to another event.

  Look at the producer/consumer (events) design pattern which comes with LV for an example.

  Lynn

• Control of the event: how to stop the race while loop within a structure of the event

  Hello

  I have some problems with control of a while loop inside a structure of the event (see annex VI).

  I have 3 buttons (the "Start measurement, stop, exit the program"). When a measure is running, it should be possible to stop the measure by clicking on "Stop the measure", but it does not work.

  Someone at - it an idea?

  Thank you very much and best regards,

  Michael

  Hi Michael,

  create a process parallel to your measurement. You can use the design model "producer/consumer with vents. You'll find it with «File-> new...» ».

  Another possibility would be to remove the "lock frontpanel" sign, in the case of event start measurement.

  Mike

• How to stop the While loop in the Structure of the event with the same button?

  

  Hello

  I have a problem. I want to use a single control to activate an event in a structure of the event and the same control to end a while loop in this case.

  It is possible to use 2 controls to do this, but I need to be alone.

  Thank you

  You should NEVER place while loops inside the case of the event, and it is never necessary to do. Think about it: all you have to do is spin the code. You can easily use the outside while loop for everything. Simply place the code of the loop internal (without the inner loop) inside the case of delay and manipulate the time-out period between a pending finished and the infinite (-1), depending on the State of the Boolean value.

  A very simple example (LV 8.0)

• How to control a VI (with a while loop and a structure of the event) from an another VI

  Hello

  I have the main VI which I want to be driven from an another VI. But I can't do that and I don't know what is happening.

  For example: VI main, I have a while loop with a structure of the event, there is a Boolean controller controlling a Boolean LED, which is inside the structure of the event. And the other VI, there is just a Boolean controller and functions of applications to open the main VI.

  How can I control the Boolean LED in VI main, changing the State of the Boolean controller in an another VI?

  Thank you.

  There are different options, but depending on what you want to do. For this example I can't give you a specific solution.

  I do not understand why you do what you do. Why do you call your 'principle VI' dynamically? What is the advantage to do? There are also other ways to call a VI dynamically, based on real cases (for example the method "call and forget", etc...).

  In you principle VI, control you Boolean ("THATCHER") is not the case of corresponding event. This is not usually a good practice, keep it inside.

  Also, why you try to communicate with the caller and callee VI through such a way to twist? There are better ways to do it.

  In one of my projects, I use the user event to launch orders in case of case of appellant VI.

  some Associates more readings for you:

  http://www.notatamelion.com/2015/03/23/how-to-make-dynamic-subvis/

  http://forums.NI.com/T5/LabVIEW/Dr-Damien-s-development-event-structures-III-communicating-with/m-p/...

• structure of the event + while loop

  Hello, I am trying to understand how to unite two while loops in attached VI for half a day

  The first loop creates a state machine solid which reacts on each key and runs one of the structure cases. (that part works very well)

  The second loop, always generates the random number, but it stops the generation during the time where one of the structure cases events are executed. (this is the part ticky)

  Any suggestions?

  If you want your random number to stop so that the user triggered events are running, you should be able to simplify your design a lot.

  It can be done with a loop using the case of timeout.

• How to reset a while loop based on a value change event?

  Hi all

  I work in a labview program that sends voltage to a laptop via USB 6008, tension is amplified by an op-amp, and then he comes back in the laptop. I created a program and a working circuit, but my current challenge is how to reset the average of the values of voltage coming into the laptop, after that the user changes the digital control (which controls the output voltage). In other words, I need to be able to reset the number of iteration and the sum to 0 each time this happens.

  I looked upward to reset the counters of iteration through shift registers, but I'm not sure it will work in this case, but I'm also not sure how to reset the sum of an array (if possible). I have spent a lot of time to read these forums and tutorials from various sites, so I think it can be done with the correct nesting of the case structures, structures of the event and while loops, but I don't know how. I am new to LV, just started to learn in mid-January, so any help is appreciated.

  Thanks in advance,

  Graeme

  You just need the structure of single event with the bargains.  Use the case of timeout to get your new values and find the average (100ms timeout value and get rid of the wait function (ms)).  Keep the amount and the number of items in the shift registers.  Wire these values through each case of the event.  In the event of changing the value: control, just set the values to 0.  Then add a Stop button value change event to stop your program.

  

  

• Synchronization of 2 loops while one with a structure of the event.

  Hi fellow users of LabVIEW

  I try to incorporate a structure of the event in my current exisiting VI to Save certain values of control as shown in this post

  http://forums.NI.com/T5/LabVIEW/using-the-quot-make-current-values-default-quot-as-a-control-on/TD-p...

  It's the VI that I use as model with my exisiting VI.

  http://forums.NI.com/NI/attachments/NI/170/547715/1/defaults%20Demo.LLB

  In case the 'stop, change the value' I use in the main VI and a 'real' constant instead of Boolean control of wire structure. While the loops are not connected. The table that I use in my exisiting VI (another while loop) is indexed and unbundled to be used here.

  The work combined well screw and it gives me the results, my question is, in the long run it will give me issues. Do I still need to synchronize?

  Thanks for all the help.

  There's no problem because loop additional lower with the structure of the event.

  Personally, I worry about the top loop. Why so complicated? Why so much duplicate code? Why all these hidden indicators serve as local variables?

  Why don't simply place you the table in the entire cluster in a shift register and the index and ungroup by name wharever value, that you need to access. No hidden local variables or indicators.

• stop another WHILE loop

  I have two while loops running independently.

  The first has a Structure of the event that controls the STOP button for a user by clicking.

  The second series a bed to a port.

  When I get an error messages entering the serial port, I want to provoke the other WHILE loop stop.

  What is the best way to do it?

  Connect a case structure wire to the error and write to a signaling value property of the button stop in the case of error.

• LabVIEW 2012 while the structure of the event does not stop

  I am LabVIEW 2012.

  An example of a while loop with the structure of the event inside can not be stopped with the stop key, Boolean.  Something wrong?

  Please see the attached VI.

  Thank you.

  Yes, something is wrong. You must add one for the event in order to detect a change in value on the stop button.

  The thing is now your structure for the event rest waiting for one of the event which she handles and ight now, it handles the "close panel" event, the 'timeout' event is too manipulated, but since you do not have anything related to the terminal of timeout (top left of the structure of the event) the timeout is - 1. So, when you run the VI the while loop is stuck in the first iteration and is waiting for a sign nearby, the stop button will only take into account after that same structure intercepts an event; I think it's because LabVIEW will execute the code related to the Terminal stop of the while until after the rest of the code that he has completed execution of the loop.

  Hope this helps

• Structure of the event inside while loop

  I'm still fairly new to Labview and this may seem a simple question.  I'm doing a Subvi to display, edit, and create configuration files.  I use a ListBox to list all sections of a config file and structure of the event to update the values in each section, when they are clicked.  The problem is that the structure of the event seems to be a break the while loop so that the buttons do not work until the event has executed.  What I would like is the while loop to run continuously and the event to run only when I click in the listbox control.  I hope this makes sense.  There is a peak in the diagram below. Thank you

  There are a number of issues with your code that could cause problems:

  1. You must use the FP. Open method to open the front panel of a VI and of the public Service. Close method to close. I don't remember exactly the problem, but starting with the 7 worm nor indicated that these methods were the preferred way to perform these tasks.
  2. Based on what seems to be the code, the event for the control of Presets of wood should be a change the value - not a mouse down event. After changing the type of event, use the event data NewVal to drive the indexer table index entry.
  3. The buttons Ok and cancel them should be handled in their own events to change the value. The value change event Cancel would exit the loop, while passing the output error (which indicates that cancel was pressed) and default values for the other 4 outputs. The change of the value Ok event would leave the loop by passing the values that the operator had concluded the 4 controls on the front panel.
  4. An event of timeout with a very short time (1 msec) would stop loop if an error has occurred, or the output of the gate AND is set to true.
  5. The wait function is not necessary, as is the case outside the loop structure.

  Mike...