Restart a flat sequence

Similar Questions

• structure of flat sequence for benchmarking

  Hello

  Maybe this is very obvious, but I don't completely understand something with the sequence flat structures-FSS (I never use this structure by the way and I don't you not why they use it in this example).

  There's a doc OR online explaining some mistakes of rookie in LV:

  http://www.NI.com/newsletter/51735/en/

  The doc has described that the FSS is useful for benchmarking, the BD:

  

  My question: what if we put the number of cycles in a Subvi left and right and giving the exec. order with wires of the error? Or using a while loop that runs only once (with sons of error through)?

  These 3 different ways are the same?

  Yes, you can do all these things - I think that the only thing to keep in mind is that you do not want your benchmarking code to affect the speed of the code - otherwise, you'll get inaccurate results. If you use the while loop, you will need to do something to make sure your second number of cycles will run after your time loop - for example with FSS

  Flat sequence structure using is OK - it's overuse of it which is a common rookie mistake - trying to force things to run in a specific order (for example if from a text based on the sequential programming language) instead of understanding that this is done by data flow in LabVIEW.

  I think that the reason is simply because the number of cycles VI doesn't have an entry so you cannot apply data flow. It is common to have a Subvi, which encapsulates the number of cycles VI with error/output wire.

• The speed of the flat sequence?

  Hello

  What I want to do: read a map OR 6 analog voltages and provide a few analog/digital outputs from another card of NEITHER.

  Here's what I do: I use the DAQ assistant to acquire 6 different analogue voltages on a simulated map of NI 9205. I tried to run at the same time all 6 data acquisition assistant acquires (which did not), but I read that since there is only a single clock on the map, so I can not use multiple acquires at the same time because of timing issues (right?). Then, I put my DAQ assistants in their own images in a flat sequence then they would be operated sequentially. This works fine, but each frame/acquire takes 1 second to complete. Which means that my program lasts 6 seconds to do everything acquires it, before my other code outside the plate sequence. Outside platform sequence are my trips (some digital and analog a bit on a slider). Because my flat sequence lasts 6 seconds to compete, my outputs are updated only once every the 6 seconds, where as before the flat sequence has been inserted that they have been updated little almost instantly.

  Here are the questions: can I do the flat sequence run faster? Or is there a way to simultaneously acquire several analog voltage using the DAQ assistant. I feel that I shouldn't need to the apartment of sequences, but do not know a better way to go about it.

  I hope that makes sense and I'm pretty new to labview so feel free to add many details.

  Thank you!

  PS: If you try my Vi, notice how slowly the 3 top entries in the page update, if I remove the huge flat sequence, they run very quickly and smoothly, which is what I would like.

  e g m e n i wrote:

  Here's what I do: I use the DAQ assistant to acquire 6 different analogue voltages on a simulated map of NI 9205. I tried to run at the same time all 6 data acquisition assistant acquires (which did not), but I read that since there is only a single clock on the map, so I can not use multiple acquires at the same time because of timing issues (right?).

  Instead of trying to run 6 assistants for the acquisition of data in parallel (or sequential), use one assistant DAQ who reads all channels simultaneously.

• How to stop a flat sequence (or timed sequence) which is inside a loop for

  The problem is this, I have a loop that repeats 10 times and inside this loop, I have a flat sequence (or timed sequence) with four images, each of this chassis to evaluate a different condition of a vector that I introduce.

  What I woud like for example is:

  I'm a fifth County of the loop for and in the case that part 2 does not meet the condition, the sequence of dish (or timed sequence) stops and starts the loop again but this time for the number of number 6.

  I would appreciate your response.

  You can't stop a sequence structure.  This is how they are made.

  What you should consider to get rid fo structures sequence and to change a state machine architecture.  There are many examples in LabVIEW, as well as on the Forums.  The big advantage of the state machine is that at the end of each State, it examines the conditions and determines which State then run. And that is exactly the description of the problem you are experiencing.

  Lynn

• Front Panel does not (exactly 2 even while in flat sequence loop)? LabVIEW BUG?

  Hello world

  I have two while loop with exactly the same code and a user in each loop event structure,

  They both make the same thing which is too run until IMAQ image control (one line) click on a recording.

  I used a flat sequence to manage the order of execution.

  The problem is when I use only one single loop (put another in a diagram to disable) the façade answer perfectly and the program does what it should, but when I activate the two loops stuck in case of timeout...

  I do not understand what is happening that I can't do any activity of façade that would be registered, enclosed is a copy of the VI (you need NIVision run the vi).

  Any idea? Is this a bug or did I do something wrong?

  Thank you very much

  Best regards

  This isn't a bug, but the expected behavior. You cannot sequence structures event like this, they both need to be ready to react. Use a single event structure and a state machine architecture. You have about 4 copies of basically the same code of event management. Try to combine everything in one!

  What happens in your case?

  Answer: The two structures event will begin immediately queues of events, but the second event structure cannot respond to them because it is inaccessible due to data flow. In addition, the second structure of the event is set to "lock the front panel until the end of the event. Given that the event cannot end as explained above, the façade is locked up forever.

• Scripts (connect a Terminal to a flat sequence Structure)

  (script)

  Is it possible to connect a terminal to a flat Structure of the sequence?  (in my case, with a single frame)

  (with the "Connect Wire" method)

  Ouadji wrote:

  but the main question is... Why the flat sequence structure does not inherit from node?
  Why the developers chose this?
  What is the main idea of this choice?

  Flat sequence Structure introduced in LabVIEW 7.0, provides a semantic schema object that no other object has. It is a structure of multi-frame (like a case structure or a stacked sequence), but it is the only structure where data can be wired between frames through normal tunnels. It is the only structure which may have tunnels in places other than its external borders. It is the only structure that can have subdiagrams of different sizes in different positions. It also introduces scenarios of strange wiring that you won't find elsewhere:

  

  At the same time that the flat Structure of the sequence was introduced, there was enough of these bizarre scenarios with scripts (which was an internal feature NOR at the time), it was easier on the developer to make his own script class to try to find a way to support it under an existing class. We had no idea that script would become a public service someday, so the burden was relatively low and limited within the walls of NOR. Looking back, there have been enough problems with the FlatSequence class in the script than most of us agree that it would be better to have it in class Node (or more precisely, the class MultiFrameStructure) from the beginning.

• Delay the time of flat sequence Structure?

  How to delay the moment of execution for flat sequence Structure?

  Your question is a little vague.

  You want to delay in a certain amount of time? Until something happens?

  You can add a primitive frame with a wait.

  It might be useful to you could reach a simplified example so that we can better see what you're doing.

• Replace the flat sequence Structure?

  I read a bit in the forum and a lot of people discouraged to use the structures of the sequence. Here's the situation: I have a tick count at the beginning for the iteration (and another at the end). I want to force them to count before (and after) anything else. The code I'm working on leash all data through structures flat sequences that contain only tick counts. Is there a different way that you can do without the structures of the sequence?

  Thans

  The recommendation not to use structures of sequence applies to most of the cases where people use.  State machines are the preferred (and best) method.  However, this does not mean that there is never a good use for a sequence structure.  In your case, when you both want something, it is perfectly acceptable.  An example is shown in the first snippet below.

  There is an alternative however.  You can use a timed loop to time your code.  Someone posted here once an example.  I forgot who he was and who puts in.  It went something like the snippet of the second.

  I would like to know why there is a difference in speed between these two methods:

  

• Why a while loop does not start in a flat sequence if I have another loop running in a different sequence of flat?

  Hi all

  Basically, I'm in the order of many device and regulation for that pourpose, I created a sequence of plate to do. Also, at times I have start the potentiostat measures I use too, which follows a sequence and I created a second flat sequence to do this. In a part of my experience, I want to follow the voltage and current of high voltage power supply that is located in the flat main sequence and also read the results I'm getting with the potentiostat simultaneously.

  In the main sequence, there is a constant bollean which triggers the beginning of the secondary sequence. In the framework after it contant Boolean, I have a while loop in which I read 2 analog inputs of the power supply high voltage with my USB-6218 for awhile every 100 m, my problem is that the Boolean constant actually starts the subsequence flat but when it reaches a while loop in which I continue to read the results of the potentiostat , for a reason that the operation does not start until the while loop in the main loop is not finished.

  I communicate with the software of the potentiostat through a driver made by the manufacturer.

  Is it possible to read analog inputs with USB DAQ and simultaneously read the results of the potentiostat?

  Thank you very much

  Without being able to see the code, can only speculate. My guess is that you have probably some data flow to the second loop that depends on the first loop finish.

• In the case of flat sequence LED

  Hello

  I have 2 flat sequence event with 1 LED in each event. How can I turn on the LED when the start of the event and the OFF when the event ended before he will move to the next event.

  Help, please.

  Thank you

  Those who are not in the sequence of events. These are individual images. Events in LabVIEW are something completely different. Based on your question it seems that you are not completely understand dataflow. A function/VI will run when all data on the cables connected to it is present. Stream can be used to enforce the execution order, but executives of sequence can also be used.

  In your first picture if you wire a real constant for the Boolean value, you can control when the Boolean value is updated because there is no dependenct data between the numerical calculations and writing of the LED. So, if you want to turn on the front LED the first image, then you must add a frame before the first person where you set the indicator and the same thing at the end.

• How can I change a variable in a flat sequence and pass it through the sequence at the exit of the Arduino?

  Hi all

  I'm changing the value of the pressure on a Governor for some time intervals, i.e., 20 5 sec then 2 sec 5 lb/po2. Since it is an easy task, I decided to use a sequence of flat but I couldn't take the pressure value and feed it into the Arduino PIN. I'm sure that it is an easy task, but I'm not good in Labview.  How can I do this?

  Thanks in advance.

  This is a very primitive solution (I do not have the makings of the arduino, so I left that.)

  

  Note that this is not very scalable. To get the best control use a wait state and the elapsed time of VI express to determine when to go to the State following the election.

• Use of DAQ in flat sequence

  Hello!

  I have a problem with my program.

  I made the diagram below. I pretend to control a bipolar stepper motor with data acquisition and a l293d, so I did the sequence

  the coils requires with the plate sequence and structure of case extern just reverse sequences. It works as I thought, but,.

  When I connect the daq 6008 apparently not to receive data. I think it's the sequence of plate, because I tested the daq with

  another program with just a while loop and it works good sense.

  Please someone explain this to me... Thank you!!

  

  and Yes, I'm new here

  A race condition is a situation where two or more parts of the program can operate independently of the other and nothing in the controls of the program or the forces of the order of execution.  In the image code you've posted local variables in the first frame of the structure of sequence may be run before or after those related to the DAQ Assistant. Of course the structure of sequence ensures that the local population in the 2nd, frames, 3rd and 4th will work later than the first image. That won't happen in reality but in principle the entire file + sequence casting structure run before the people of the country connected to the DAQ Assistant have been read. Then, you would get the last value onley.

  To fix it, learn how to leverage the data flow. Create a 2D of the Boolean array. With the help of Autoindexing on a loop for, read one line at a time and it wire to the DAQ Assistant (also inside the loop). Look at the VI attached.

  Lynn

• flat sequence stops after the first image

  Hello

  I use USB-6218 to drive a current source and read the voltage at the terminals of shunt resistance in my circuit. In order to safely run things, I wanted to make sure that when I stop my blood 'on demand' vi, I updated the current 0. To do this, I tried to use the sequence of dish (find in annex vi), but my program never leaves the first image, even after it hit the stop on my front button.

  Can someone help me with this?

  Thank you
  Katarina

  Does not change the value of Stop inside the Subvi and the loop runs continually.

  -Suggest to check this example: http://www.ni.com/example/28769/en/

• Elapsed time in flat sequence Frames

  I enclose a VI file simplified what I'm trying to do. Ideally, this program starts when "OK" is pressed and cross frames (or steps) to the time indicated as wait times. The program would then reset. It will be meant to time the experimental stages, possibly with release of equipment parameters. I wish I could have a direct timer for each step backwards (ideally) or to give elapsed time. I tried different variations, but nothing seems to give me a direct timer as I'm looking.

  This timer is not entirely necessary, it would be good to know where experience is the place to experience 50 hours that makes us turn.

  I am very new to LabVIEW, please excuse that requires the simplicity of the solution that it likely.

  As a simple state machine, it is trivial. See if the attached VI may give you some ideas.

  Note that since this is a state machine...

  • It can be stopped at any time. If you allow only stop in the slow case, don't wire in other cases.
  • No local variable!
  • No loops inside loops!
  • No sequence!
  • A unique array of clusters setting information specific to the State in one place. Nothing distributed across multiple locations.
  • All States timer reuse the same code, just with two values different (State and duration).
  • For more complex scenarios, you can add more flavors State.
  • Note that I use the output of waiting for the tick ms. (you can also use the number of cycles, but who would need a separate waiting)
  • Simple, scalable, and extensible code. Just add items to the enum and add corresponding cases.
  • modify if needed.

• How to create flat sequence structure and add Subvi with true or false on an another flat following?

  How can I create next. flat and add a colum with VI and true Sub VI falseSub?

  What should be the flowchart: