Code Golf: stop two while loops with guaranteed ratio iteration

Similar Questions

• Stop a while loop with outdoor table

  Hello

  I have a problem to stop the execution of a vi that uses a while loop and outside a table with two values of time intervals. I would like to stop the VI when the different values of the array are passed. I have attached here the code if you want to help me please, thank you in advance.

  
  

• Stopping at two while loops, running with queuing

  Hi all

  I'm using labview 8.2.

  I have two while loops in my code (called the main loop and the other average loop - seen on the screenshot file).  I just want to stop both the while loop at the same time (it's ok it the average loop takes a bit longer).  I use global variables to stop (as I have tried the local one, but I don't think that LabView sees in the middle of the subroutine).

  Please give me some suggestions on this.

  Is attached a screenshot and my labview code

  Using a ' functional global' is almost identical with a "global" variable Indeed, before the existence of "global variables", a functional overall, it is how people have this feature.

  The usual way to stop a loop containing a "wait for queue ' is to destroy the queue and use the error on the terminal of the 'expectation of queue' directly in the terminal of the judgment. In this way, you don't have to queue up some kind of end the command to stop it.

  Add a queue to destroy after the stops 'main while loop. Delete the global variable and the error from the stop "waiting in the queue" in the loop "average" it is wire terminal.

  General advice, always try to avoid using local and global variables.

• 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 use a structure of the event to do so, but it seems not elegant or the right way to do it.  The only way I could get to the kind of work is by unchecking the lock front panel in case of structure.  I have attached a sample vi of what I have so far.

  The problem is that you can't even stop the program by pressing the stop button until you exit the tab, which is not a user friendly interface.

  The event should just manage basic user events.  Any given event does not take a lot of time to run.  While you are in the diagnostics tab, your code is stuck in this while loop.  Although the setting of the front panel of the lock allows you to do other things, the LabVIEW is just put on hold all these other events of the UI (like Stop button value change) and cannot handle them inside while the loop stops and allows outside while loop to go through again.

  You should have a parallel while loop to manage waveform graph.  You can use notifiers or queues or a motor of action FGV (see Ben Action Engine Nugget) to switch the starting or stopping of the update of the chart of waveform until the parallel of while loop.

• How to exit while loop with delay schedule?

  I have a pretty heavy program that iteratively takes a series of measures from a number of channels using a variety OR-Switch and OR-DMM screws that I assembled as a result of various examples and several help pages. Each channel is sampled once during each iteration with data to be saved in a text file for later analysis, after it is imported into Excel. I added to the screen 'real time' indicators and charts to see what looks like running data.

  Each iteration is performed using a While loop with a delay timer, even if a previous version, I used a timed loop. Measures for the series of channels are collected with a loop For inside the While loop. The loop For includes screws which:

  1 cut the channel and wait as debounce.

  2 Initializes the DMM and passes the configuration information.

  3. wait for a while to make sure that the DMM is set.

  4. measure.

  5. close the DMM.

  6 disconnect all the switches.

  The terms of the election of the channels is ends in 15-20 seconds and I am currently collecting data every two minutes, so he spends "wait" time "collection". Each iteration of the loop For initializes and closes the DMM to avoid the hot switch.

  Other components of the program are configuration setting controls, etc. (in front of the While loop), a "current measurement" indicator and a writing-text inside the loop file operation For, several indicators of the iteration (inside the While loop, but outside the loop For) and a bunch of operations related to the grouping and table that provide graphics of groups of time vs measures.

  I don't know there are more elegant ways to perform many functions that I do and I'm not posting the VI here because I want to concentrate on what I know, it's a big problem with my program (for now!) - I can't figure out how to get out of the While loop. I tried the combinations of Boolean control, its conditions of latch and Stop / continuous if true to nothing does not.

  I want a 'Stop' button that ends the While loop, at the next opportunity, but it is not working properly, I think, because the stop button does not play with good timing, because the program runs either the loop For or the time delay at the beginning of the While loop. 'Next opportunity' can mean 'Immediately', 'at the end of the next iteration of the loop,"or"at the end of the next delay schedule." I think that if I get one of these scenarios to work, I can get an any of them to work!

  Help, please!

  
  

• 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.

• Stop a while loop in a sub - VI in a message in queue manager

  Hi all

  I am trying to program a control for certain manufacturing equipment. For this I use a message in queue manager. Within the QMH, I have a VI that controls a particle size probe (called a PPC, at the bottom of the first image. When I start the main-vi, the PPC.vi is on the case "Parsum measurement", in which measurement data are repeatedly called in a while loop (screw for call data provided by the manufacturer of the probe. Also, I am aware that I don't connect the data again. That will come later.). When I want to stop the measure, I have send the message "Exit" to the PPC.vi (last photo). However, the vi is stuck in the while loop in the case of the measure and is unresponsive. I tried to send a notifier with a constant value true, but that did not work as well.

  You have any suggestions, how can I stop the while loop before you send the message "Exit"? Or is the completely different way to approach this problem?

  Thank you!

  

  

  

  I just threw together a framework very fast to help you get started.  The thing I noticed is that the library of the queue doesn't have a time-out of the waiting message entry.  Since it is your own local copy (to the project), add a timeout and connect to the element Dequeue function.  I by default set to-1 and make it "recommended".

• How to start and stop two parallel loops?

  Hello

  I want to control two parallel loops with different timing in a vi. Second, it means that to start the loop 1, roll 2, stop 1 or 2 restart loop 1...

  But if loop 1 turns that I can't start looping two then reverse.

  Can someone help me and show what is bad in my example?

  Thank you

  Christian

  Hello Christian,.

  The reason why you can't do what you want is actually quite simple.

  You have an external loop which is 'on' the two inner loops.

  So when you stop one of the inner loops, the outer loop will still be in the same iteration until the other inner loop ends - stop the other inner loop.

  You can see very easily if you explore the outer loop iteration count - only when both loops internal, it is incerment.

  So, to do what you want, you need to make them independent - you need two external loops.

  Check my attachtment, see if that's what you need.

  Hope this helps,

  Paulo

• loop for and while loop with empty table entry

  Hello

  I have a question with loop and loop.

  When a constant empty array (zero element) is connected to the loop For with "allowing the index", there are no interactions performed in loop For. But, if the loop is replaced by any loop, no problem.

  LabVIEW 2010

  Hello

  It is ok. I have no problem at all.

  For the 'loop' For when you connect the table thanks to indexing, the number of iterations is set to the size of the array. The iteration number assigned to N (in your case 10) is ignored.

  For the 'While' loop the number of iteration is defined by the Boolean Condition and the size of the array is ignored.

  Paul

• While loop with stop unwired FPGA button?

  I've seen examples FPGA with a while loop where nothing is plugged to the stop button. On a target PC, it would throw an error. What it means?

  I think you are talking about "Timed loops" that are "single-Cycle timed loops" on FPGA.

  FPGA is intended to be run until it is powered, a 'Stop' software does not much sense.

  Norbert

• 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)

• While loop with reading of text file - calendar of events in a given period

  Hello world.

  I created a program that if serial interface via a port to a syringe push in my lab. Currently, the program reads in a text file-flow rate values and sends them to the pump, one by one, through various commands. I need to ensure that whenever a new flow rate value is sent to the pump, it does in a specific/hard time for a while. I.e. every 0.1 seconds, changes in flow rate and must are active until the next period. I tried to use a timed loop and I think I've succeeded, but it hogs system resources, so I was wondering if there was a way to do it using the number of cycles or something of this nature. I just started using LabView, so I'm slowly getting the hang of it (easy when you watch my VI!)

  See attached VI. I took orders from serial port and have instead orders display in an indicator. The nested and densely populated while loop contains the commands that need to be completed/last during the period (like 0.1 second).

  Thank you for your time and help!

  -Phebotalus

  Hi, you should read some introductory material on LabVIEW to down the idea of the stream.

  Basically, the data flow in the wires from left to right, and any node will not work until it has reached all of his contributions.

  The thread of the error is the best way to run data streams.

  ***

  In your VI I use data wires, their execution through structures, and forcing the structures to run in the sequence.  Using a structure of sequence you mentioned in your next post will force the two scripts to execute in the order of (the only one we discussed to be in race condition.)

  Similarly, for brevity, I would wrap the EMO and she is business structure in a single sequence and force it to run last using stream.  In this way the user has the most possible time to decide to hit the EMO before she is called by the application.  As it is now, it most likely is interviewed at the beginning of the loop, so if it's the exchange value you won't see results until the next loop.

  When running in execution of highlight you see the order of data flow, but that is not guaranteed to be the same for a normal performance, where the use of the data stream.

  ***

  The counter tick account ms up to a very large number and then "says" reset and start counting again.  I know you want to START the loop as close to every 10 ms.  Yes, using data flow, take the number of cycles first, perform actions, then return the number of cycles.   The second time of the tick read that you are in a nested loop that does not stop until you get 10 or more difference on the number of cycles.

  And, on the off chance that you must achieve "return" on the tick counter comes stops the nested loop then move.  (if the second measurement is less than the first, then the tick counter handed.  If you miss this situation while you'd have to wait a long time for the condition of the difference > 10 in the reunion, basically locked in the loop.

  ***

  You could put the EMO sequence, we have seen, in line with data streams.  Before or after the second control of ticks will not make much difference in terms of 10ms.  I would put it after checking the tick, again give the user more time to hit the EMO if necessary.

  ***

  I put in a queue for the stream error and removed the other stuff.

  LV2010

  Check out some of the LabVIEW intro docs, they are online, they discuss these issues and much more.

• 2 parallel while loops with functional overall to share data

  Hello

  I'm having a problem with the sharing of functional with globals data between two parallel while loops:

  1. One of the loop (bottom) generates a random number periodically and write the total functional sample.
  2. Another loop (above) has a structure of event and when it expires, he would read the functional global and intrigue, a chart data point.

  The problem is sometimes the functional overall seems to be 'locked' and the output becomes zero constant. It also seems that whenever I first open the VI, it works fine. But for the second time running, he begins to have the problem.

  

  You must initialize your VI stop FGV FRONT of your lower loop begins.  Even if you use a global variable that is functional, you have a race condition.  FGV is read in the lower loop until it had a chance to be initialized with a value of false in the upper loop.  Functional global variables do not forget their data between executions of the VI.  So it is always set on stop the last time that you ran the VI.  This works your VI the first time it's because VI does not have in memory, so when it loads, it loads with the default value False in the shift register.

• How to increase code efficiency in a while loop (using PXI5105 for sampling outside signal digitalizer)

  Theoretically, we want the PXI-5105 (digitizer) have 302 record with each record has a 1260 sample (the save operation is inside a while loop) in approximately 30ms, however we have found that for each period (30ms), the PXI5105 only perform about 10 records. It is so wired. I wonder if the operations inside the while loop consume more time (for example 3MS), so that he cannot have 302 records even the PXI-5105 have 60 M/s speed of sampling. Is it true, you can find my labview code and if possible can you give me some suggestion in the most short time of operation of the loop.

  

  Please find attached labview code.

  Hi g_l_g_s,

  The digitizer PXI-5105 acquires data at the speed that you specify and stores the data in its memory embedded (up to 512 MB). The data is then sent to your computer when the Multi Fetch Cluster.vi is called. In VI that you posted, you are only fetch record during each while the loop iteration. If you want to retrieve 302 records you will need to specify 302 files in the horizontal Timing.vi to configure. For more information about scanners, you might find the DevZone, hereuseful.

  To determine the amount of time it takes for each while the loop iteration, you can consider using the structure of code in the example comparison community calendar, which is located here.

• problems of operation of two while loops in a VI

  Hi forum,

  I am developing a project for the acquisition of data continuously for two types of signals (voltage and temperature), each consisting of 20 channels. The sampling frequency is different so I used two call loops of different period to take account of the sampling frequency. It is within the VI that is deployed to the target device. On the host VI, I have two loops while put each containing a VI write_to_measurement express so I can connect the data to two different filepaths. However when I run the program, that a signal is registered correctly while the signal remains would have only one row of data. Looks like one of the while loop is only on the iteration while the other is running smoothly. This is an example of the famine of memory? How can I solve this problem! Any help greatly appreciated! Thank you!

  Vincent

  What asked Fan Ravens is why do you use static variable to stop the loop?  You do something remotely?  Simply use a local variable in your second while loop to stop him.  You need to change the action of the button stop, but that would be the way to do it.  Stop buttons are perfect for debugging and development, but generally I will use one other mechanism to stop the program runs outside the environment of LV.