Re-start producer while loop

Hi,
I'm trying to figure out the best way to implement a producer/consumer architecture. I'm hoping there is something simple that I don't understand.
I have a state machine executing in it's while loop, doing things like saving and processing data. The data is being passed through a queue from a separate while loop. I'm currently starting that producer loop using occurrences, and I can stop it with a local variable.
What I can't figure out is how to restart that loop from within the state machine? In essence, I'd like to have a switch that says "Collect Data" and it will turn the producer while loop on and off but leave the main program running in the meantime.
Thanks for any suggestions.
mike

Basically, i find producer/consumer architectures where the consumer creates "commands" (Edit: which do more than simple notification tasks) for the producer quite absurd.
I would switch to a three loop architecture:
Producer A is responsible for UI display/control. It feeds Consumer A which is infact Producer B.
Producer B (aka Consumer A) is the DAQ consumer. It will acquire data due to the settings passed by Producer A. The DAQ data will be passed to Consumer B.
Consumer B handles the data passed by Producer B. If necessary, it can create custom user events in order to notify Producer A about certain situations in the software.
An approach with an Action Engine can be similar in regard to functionality, has its own advantages and disadantages.
hope this helps,
Norbert
Message Edited by Norbert B on 01-14-2010 12:13 PM
CEO: What exactly is stopping us from doing this?
Expert: Geometry
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Starting new while loop while old one still running

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Thanks. I suspected as much. In any event, I can't seem to find a good configuration of while loops and case structures which will produce the desired results. I want to start acquiring images and allow the user to choose to start recording at any time he desires. This issue is further complicated by the fact that the status of the "Start recording" must be checked at all times, but only initialized once, while the AVI Write Frame depends on that first initialization step but must be looped continuously aferwards in order to 'keep up' with the images being acquired. In the newly attached example, I placed the case structure inside the image acquisition while loop and the avi write frame inside a while loop inside of that case structure. unfortunately,
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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.
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Yes I would like to run a while loop only after I switch on a start button. For some reason the loop does not start. I put the while loop in a Case structure which I want to make true with the start switch.

Hi,
ALT 1: If the button is false, the case does nothing, and the program is
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(that quits whenthe program is done), or use the run continuously button to
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ALT 2: Make a while loop before the while loop that you have. Wire the
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Regards,
Wiebe.
"JShaw" wrote in message
news:5065000000080000003C80000
[email protected]..
> Yes I would like to run a while loop only after I switch on a start
> button. For some reason the loop does not start. I put the while loop
> in a Case structure which I want to make true with the start switch.

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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.
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LabVIEW 8.2 - 2014
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How do I create a start/stop button for each separate while loop within my program, when each of them does a different task?

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iZACHdx wrote:
Hello,
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-Zach
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"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
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Hello guys,
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[http://www.speedyshare.com/794260193.html]
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Is my question not clear enough? Do you need more info? Or is nobody here familiar with javax.sound.sampled?
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Start, stop and restart while loops

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Stop and start while loop on order

Hallo everyone,
I have this small IV, it means nothing but I want to know if it's possible to control each while loop. what I wish to do is to press the boolean button, then the while loop starts running and when i press it again the loop stops but when I press it again it works again, not that the program stops running at all. not only that but I need it for both loops. so i run one and stop the other then stop one and run the other and so on...
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Attachments:
Unbenannt 3.vi ‏178 KB

pcardinale wrote:
Perhaps something like this.
I don't think we need to involve such a huge amount of code and new concepts (timed loop, notifiers, subVIs, clusters, arrays, event structures, etc.), to solve such a simple problem. (This might turn off a beginner!).
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LabVIEW Champion . Do more with less code and in less time .
Attachments:
TwoCharts.png ‏14 KB
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How to start/stop 2 parallel while loops

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Attachments:
screenshot.JPG ‏74 KB
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SnowMule wrote:
Starting the two is easy; use the error cluster to enforce dataflow.
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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

Starting stopping multiple while loops

I have a rather large VI that runs multiple while loops with case strutures inside.
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Solved!
Go to Solution.

Do you want something like this?
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While loop doesnt start

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organLog.vi ‏149 KB

You have to familiarize with the basic concepts of dataflow. Look at some example programs. Do some online tutorials.
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LabVIEW Champion . Do more with less code and in less time .

Timed Loop in Producer/Consumer Loop

Hello!
I have a producer/consumer loop LabVIEW program setup to allow me to properly capture images that are quite large (8MP) at approximately 14 frames per second (FPS). The program works great when the consumer loop is a 'while loop' (records at 14fps no problem), but I wanted to make it into a timed loop, so that I may vary the FPS as required. An oddity arises when I do this. Anywhere below 12fps, the loop works fine and the data is recorded properly. However, when I bump it up to 13fps, the consumer calculated FPS goes haywire and starts jumping between ~9 and ~13fps (data processing gets bogged?). When I set the required FPS to 14, the loop executes at a steady 7FPS maximum. Is there something I can do to rectify this situation?
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Palanski,
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