While loop with Date counter in the procedure

Similar Questions

• 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/...

• 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!

  
  

• 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

• 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.

• 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.

• 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.

• 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

• Control and Simulation in a loop / while loop with TCP/IP reading / writing of synchronization

  Hello, I have a problem with reading TCP/IP and written in two loops. The problem is NOT to get the two loops to read and write to and from the other. This has been accomplished. My problem is when I run control and the loop simulation on my laptop and the while on a RTOS remote on the controller on-Board of LabVIEW in a remote PXI chassis, the while loop the remote system running on four 4 times faster than the loop control and simulation on my laptop. In other words, for each iteration of the loop control and simulation on my laptop, there are 4 four iterations of the while loop on the remote system. I need to know how to get a degree of kinship (1:1) with these iterations of the loop. When I run a longer simulation in real time, say 10 seconds, the control and Simulation loop begins to slow, i.e. the simulation time slows down until it is no longer in real time and the "Late Finish"? Parameter is set to true and the LED lights and continues to stay lit. At this point, the system destabilizes due to what I believe is being well sampling rate too discreet and I have to end the simulation. How can I get a ratio of one to one between the loops and also to avoid slowing the loops causing destabilization?

  To give an overview of my application, I implement a control system in a network, seen in "image2.png". This is achieved using my laptop as a subsystem 1. Reference signals are generated from the laptop and the error signal is produced. Control measures taken and the control signals are sent via TCP/IP to the remote system. Position feedback is returned, and the process repeats. My system has Core I7 Procs w / 3 GB of RAM, up to 1 GB/s speed via ethernet and LabVIEW 2011 installed with all necessary modules and networking tools. The attached VI Custom_Wireless_Controller works on my laptop. The remote system I'm working on that has the 7830 NI R Series with FPGA card. OTN runs on the PXI chassis with an enbedded controller that has networking capabilities of up to 100 MB/s via ethernet. I use the FPGA for the acquisition of data and apply control signals to my plant. The plant is the PCE twist connected to the FPGA through the cable of the ECP - RIO of NOR. Subsystem 2 is this side of the CNE. The FPGA collects position, he sends to the controller via the network, receives signals from the network drive and writes signals to the plant power amplifier that operates the plant. This process is repeated and the VI and is titled Custom_Wireless_Plant.

  I appreciate the help really and look forward for her and for any question!

  Well, the first step is to understand what you have set up right now. Your control and Simulation loop on the side of the controller is configured as 'Runga Kutta 4' and you have a loop timed on the other side. In addition, you have the primitives of TCP/IP on the control and the Simulation diagram and means he will perform (a message) on the size of each minor step, which in your case is 4.

  So, you have two options:

  1. replace the Solver side controller Runga Kutta 1 (this must synchronize loops)

  2. hold RK 4, but create a Subvi around two primitives of TCP/IP and configure from the VI to run than the major (continuous) step-size. If you do it right, you should see a 'C' on the upper right part of the VI you have created.

  Please let me know if what I said is not clear...

• 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

• Use of memory in a while loop with a xy chart

  Hi all

  I have problems using memory with a vi that loops, records data and plots in a xy running chart.  I wrote it using shift registers and functions "subset of the table", which I assumed would reduce overhead costs, but apparently this is incorrect.  If it works for several days (which is normal, because it is above all a vi for follow-up and view a trouvreez process that runs continuously), it takes a few minutes only to stop the loop.  I guess it would eventually just stop working entirely.  I googled this problem and I see suggestions to auto-index or pre-allocate.  However, I would also like to plot each point as the tracks of the loop, so I need shift registers.  What I do use some convoluted pre-allocation, changing table and then insert into the table approach, or is there a better way?  Still working?

  Thanks in advance

  
  

• run a while loop in separate vi, minimize the window flashing

  My apologies in advance for not including a VI; I cannot give it, cannot even provide screenshots.

  I have a state machine base with a cluster of Boolean values that are analyzed in the 'default' State, the scan index = true determining the next State. All other States to return to the default state. The State of 'stop' stop the loop with a Boolean constant = True, located inside the structure case wired to the time entry conditional loop (all States have a Boolean constant False wired to it). Apart from the cases

  statement, the wire connected to the conditional entry is connected to a Boolean indicator, ' Stop, in really. The time delay within the State of the machine while loop is currently set at 100 ms.

  In addition to the 'State' shift register, the state machine has a "boolean" shift register. All States, except one, feeds the value passed the Boolean value through to the next State (i.e. wired directly from left to right the structure of the case). The exception is the State which inverts the Boolean value, with the output of the inverter transferred to the State following and also connected to a Boolean flag, 'Show the State', the

  indicator outside the case statement but inside the while loop. All other States wire just the previous state of the Boolean value through the following State, unchanged.

  In addition to the State of the machine while loop, I have a parallel while loop (scourge of the LV forums). All entered conditional loop is connected to a local variable to 'stop, really. " A True/False case in this while loop structure contains a Subvi in the case of True value. The Boolean value of entry to the case statement is connected to a local variable for 'Show status'. The Subvi, which is in the real case is to display the State of the

  user.

  The Subvi which provides status through its frontage runs a script in python via a 'comand prompt"vi. The necessary update to the python command send is ~ 1/second. Within the Sub - VI is a 1 second delay time after execution of the code.

  It works but I'm doing some improvements with minimal impact on what I have.

  Two cases of VI properties that relate to the conduct of the State Subvi (floating or default, modal does not at all):

  1. with "Firm when previously closed" selected, the window switches VI (via the main switch VI) open and closed but when it is open there is the a second window flash that could cause seizures in some users.

  2. with "closes when previously closed" deselected, the window remains open and it is difficult to tell the difference between the running state and is not running. In addition, the Subvi window will not be reduced for this option.

  Is there a little invasive change, I have the code in force to stop a second flash described in #1 above and activate / deactivate the Subvi status window?

  Thank you

  Jeff

  
  

• 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

• 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.

  
  

• Data block in the procedure and the Base Table

  Hello
  
  I hava a form with a block of master and detail. The fields in the Master block are
  
  Emp_name, DateOfJoin, salary... I created this block with the procedure with a Ref Cursor, becaue the user
  want to load the data based on the conditions it enter for example: DateOfJoin < = Sysdate and DateOfJoinn July 1, 2008 "."
  SO I created a block of control with the fields name, MiddleName, LastName, of DateOfJoin, in DateOfJoin, the salary, and when the user clicks on the data loading
  button, I load the data to block under these conditions using the procedure.
  Note that in the Emp_Name table if a field, but contain first name, middle name, and last name with a separate space.
  
  My needs is, is there any method to develop this master block with a database table, so that if the user want to select it
  data based on other conditions, it can enter directly into the block of data using Qry enter and run Qry, also if he wants to
  Select data based on the top-level asked the search criteria, it will click Load Data.
  I hope that in this case, when the user selected the Load data button, I need to change the data source to the Type of procedure and set the source of data on behalf of the procedure name.
  
  Is there any other easy solution flor this
  
  Thanks in advance

  not sure if I get your needs. I understand the following:
  You have a block based on table emp, containing a DateOfJoin column and the user should be able to enter into a 'complex' where denomination.

  To do this, you do not have to base block one a procedure or ref_cursor. Two possibilities:

  Add two fields more directly in the block that are non-base of data-objects of type date fixed query on yes and let the user to enter a date range in these columns. In the accumulation of PRE-QUERY-trigger a WHERE condition by using the value in this field:

  something like:

  DECLARE
    vcMin VARCHAR2(10):='01.01.1700';
    vcMax VARCHAR2(10):='01.01.2999';
  BEGIN
    IF :BLOCK.DATE_FROM_JOIN IS NOT NULL THEN
      vcMin:=TO_CHAR(:BLOCK.DATE_FROM_JOIN, 'DD.MM.YYYY');
    END IF;
    IF :BLOCK.DATE_TO_JOIN IS NOT NULL THEN
      vcMax:=TO_CHAR(:BLOCK.DATE_TO_JOIN, 'DD.MM.YYYY');
    END IF;
    SET_BLOCK_PROPERTY('BLOCK', ONETIME_WHERE, 'DATEOFJOIN BETWEEN TO_DATE(''' || vcMin || ''', ''DD.MM.YYYY'') AND TO_DATE(''' || vcMax || ''', ''DD.MM.YYYY'')');
  END;
  

  Another option:
  together, the length of the request of the DATEOFJOIN field to say 255, then the user can directly enter #BETWEEN fromdate AND fodate in the field.