Shutdown producer/consumer problem

Similar Questions

• Producer/consumer problem: several loops/queues

  Hello

  Please refer to my previous post ... http://forums.ni.com/t5/LabVIEW/What-is-the-best-way-to-switch-between-multiple-image-buffers/td-p/1 > for more on the subject. I was told to try a producer/consumer architecture, so I decided to go and do it.

  After doing much research, I come back to ask for help.  I decided to try to implement three loops. The reason for this is because I thought that the length of each loop synchronization can be controlled independently as it should. A single loop treats all user interactions.  A single loop treats data acquisition.  A single loop about the transformation.  I hope that this would help, but obviously made things much more complex.  I created a queue for each loop.  I didn't get the full project, but it seems that everything has run very well where I stopped.  However, one of my States I did not queue receive queue and I have no idea why or where coming.  There is an error in the variant data that says

  'status'-> TRUE
  'code'->-6
  'source'-> ' error: Invalid Args.

  However there is no error in wiring.  Also when this error is displayed, the random State fell through.

  The other weird thing is the number of items in the queue jumps very quickly when I do almost anything.  I don't know if it's common.

  Before I post pictures or whatever it is, I would have an idea about this error.

  Also, I think I saw this in a previous post about the BAU, but I would like to ask a question.  Attached are two photos.  Queue 1 is the way I put things in place.  Queue 2 is the way I saw things in place.  Can someone tell me if the queue 1 is the wrong approach and why?

  I realized what happened.  The other loop was not handled properly and sent the random State of the main loop.

• First try the producer consumer Architecture: continuous play and dynamically update settings.

  Hello

  I am currently working with two instruments; an Agilent E3646A and a NI 6212 BNC. My goal is to have the 6212 continuously take measures according to predefined parameters while the E3646A parameters can be continuously updated. This combination simple instrument aims to help me learn the manual architecture; continuous measurement, output dynamic controls and instruments more will be added in the future.

  I've already posted on a similar, but more complicated configuration (http://forums.ni.com/t5/Instrument-Control-GPIB-Serial/Split-second-lag-when-controlling-two-instrum... and was advised to try the producer consumer Architecture.) I found the documentation on the website (http://www.ni.com/white-paper/3023/en/, https://decibel.ni.com/content/docs/DOC-2431), searched the forums and built my own VI. While my first attempt at a producer consumer Architecture has solved some of the problems I had when I posted on the subject, however, new questions have been raised regarding the reading and adoption of the VI.

  I am currently able to run the VI and update the settings on the device. Previously, I'd get a freeze while the instrument has been updated and could not switch settings until it was done. This has been resolved, although that reading updates only when a parameter has been updated, although it is outside the structure of the event. In addition, the Stop button does not in any context. I also got occasional mistakes on the part of Deqeue, but the major part of the sentence is error-200279 'A tried to read samples that are no longer available' to DAQmx Read. I realize that there is a problem in my loop of producer but have not been able to find a way to solve it.

  This is my first attempt at a producer consumer Architecture and already I can see that it is a powerful tool. I read as much as I could and looked at examples, but should have some problems at the beginning. Would be very grateful of any advice so I can take full advantage of the architecture.

  Hope to hear from you,

  Yusif Nurizade

  You're going to overflow this buffer, unless the events are generated faster than "sample rate/number of samples.   Period.  Nothing could be simpler.

  You don't need a local to stop your curls.

  Try something like this attachment.  I simply moved the structure of the event in its own loop dedicated since it had nothing to do with acquiring data at all.

  Data acquisition loop stops very well when you destroy the task and destrying the stops of power queue (sending the default values of the queue for the power control) for EXAMPLE, to ADD a group of setting 'Safe shutdown' to a 'package' and it wire to the Center terminal (Prototype).

• events producer consumer with notifiers

  Dear users of LabView,

  I would like to ask your advice on my project (see the attachment of files). For the beginning, I did only the "backbone" of my project, that's what you can see in my VI. My project will have the following features:

  -Start and stop action possibly (and also plot data to the chart and saving the data to the file)--> here is some time a loop to record data ranging from DAQmx (USB6009) and another while loop with rates of different loop to rise in voltage output amplifier of the magnet.

  -During the measurement, or if the system is idle, the user is able to read files of measured data and evaluate the measured data, etc... (so there will be more features...)

  I decided to use producer consumer structure with events and the authors of notifications, and I also use the dynamic user event to be able to communicate to the consumer with the producer (where I have my machine of the State as in a shift register).

  Please comment on my VI, what do you think? Maybe I should use the state machine (the shift with the pole of the State Register) in the lower loop? I could also use up queues of the notifier, but since I send only orders and the values of the parameters (not streaming broadband data) I guess that the declarant is fine?

  Thanks for the tips!

  The code you posted looks like a good start.  The architecture is very similar to the measurement sample continuous project comes with LabVIEW 2012.

  A few things I noticed:

  1. I would usually use queues instead of filers (unless you want to manage only the last command and not all orders in the order they are received).
  2. You don't need the registry change in the top loop (structure of the event).  You inadvertently send a length of measure and other commands parameter since you replace only the command.  Probably, this is no problem for now but could be a problem later.
  3. I think the user events are a great way to manage cases of judgment where the consumer is able to report to the producer that the application must exit loop (this is how we do in the sample project).
  4. Your case 'Init' confuses me a little.  It is read length control measure and send a user event in the event that, in the structure turn immediately place a measure command. Once I see a control in a loop of consumer as it hurts a bit uncomfortable. Why not have the value "start_measurement" to change event read the length of measure command and send it as part of his message to the consumption loop. Then the loop of the consumer can Init and self talk to start the measurement.
  5. You may need to rethink your strategy mistake in the case of the measure. Currently you do not stop a loop if an error occurs, and allows you to keep the error between iterations of the loop information shift registers.  Therefore, if an error occurs in one of these loops you can never hear about it.
  6. In general, using the error state as the main way to stop a loop from consumers is a bad practice. I'd rather see a "Shutdown" command which causes the consumer to stop loop. It is more scalable and less likely to be triggered by the accident.

  Good luck with the rest of your application.

  ~ Simon

• Master/slave producer/consumer Feeback?

  We know that in the models of master/slave and producer/consumer can send information of the master loop or a producer to the loop of the slave or the consumer.  But what to get information of the loop of the slave/consumer back to the master/producer loop?  I think it may return some sort of output or a message saying something like "I finished my work successfully.  This can be done with local variables, but is it really a good idea?  Is there another better way?   In addition, in this case can I just use a sub - vi?    I don't know that I always get the PARALLEL treatment offerred by master/slave and producer/consumer with a sub - vi.

  You can use a notifier to send a return message.  You can use a local variable, but unless you know what you are doing, you might encounter problems with race conditions.

  Sub - VI have nothing to do with producer/consumer architectures.  You can do a p/c with or without sub - VI.  Sub - VI is a way to break the code in significant functional blocks.

• Producer / consumer set loop of dynamic data item type

  Hey all,.

  I do a simple exercise of producer / consumer in a loop. In my loop of producer I audio Aqcuerir and in the loop of consumer I'm projecting on a chart

  Everything works as I had in mind, the only thing that bothers me is the way that I had to set the type of the element to the block "Get the tail" at the beginning.

  I knew no better way to get the kind of data that I used to just take an another "acquire its" Express VI and which hang. But that may not be the only way to get there, right?

  Note: I know that I might not need to use a producer / consumer design tend to do, but I need to get hold of technology for school work so I came with this exercise just to get a hang of it.

  Thanks in advance,

  Al.

  Al,

  You just need to feed the correct data type in this entry, which you did by getting the output of a second acquire its Express VI.

  You can also use the "Convert to Dynamic Data" function to do this.  When you drop to the bottom of the function, you will be asked to give the input type.  Tests I've done, it seems not to matter, but for example if you chose the entry to a single scalar type, you need to feed a digital constant (change to double type) in the entrance and use the output of dynamic data such as line item data.

  I don't like the dynamic data type because it is not very clear as to what it is.  Another thing you could do would be to use the "Convert from Dynamic Data" function to change the output of the VI of its acquisition to a different data type for more or less to avoid the original problem all together.

• IMAQ Vision: Is not an Image error when using producer/consumer

  Hi any person

  I used the Vision Express to solve the problem of Patern Machine.

  I want to put Assistant and Aquistion in 2 loop parallel. So I used the producer/consumer to transfer data

  After running VI, I pressed the Stop button and I encountered this error

  I think that getting the queue has a problem. I changed Image to Contant control and connect it to the data type of element. I think that this path is correct.

  So, in case of error, it addressed to Coppy IMAQ in Assistant. So I think that I used the Comunication of the queue is not correct.

  How can I solve this problem

  Thank you

  

  You can see more detail in the following video: https://www.youtube.com/watch?v=i6FOQ2jypXc&feature=youtu.be

  Try this:

  

  You should put the image process in the loop of the consumer and release it properly.

• export to spreadsheet - data 2 channels appear in alternation with loop of producer/consumer

  Hello

  I'm having trouble with the function "Export the waveform to the worksheet" - but it is not clear to me if the problem is with how I use the export feature or if I am wrong concatenating two waveforms of different modules of the series prior to export, or if my queue is wired incorrectly for producer-consumer loops.

  I use a hunts SMU-1073 with SMU-6361 and 4330 modules (tension and strain). I tried to change the example of the "entry analog cross synch" for use with a structure of producer-consumer (see VI below).

  The output of the worksheet contains a large part of the data in the string tension, followed by a smaller piece of data (with timestamp) strain, after which the alternate output data between data of tension and strain.

  Can anyone suggest where I could go wrong, or how I could solve this?

  Attachments do not work, so I'll try to post in an empty message directly after this post.

  Thank you

  Claire.

  That's what I thought.

  A number of wire.  -1 gives all the samples available in the buffer (which can be zero for some reason any).  A number will expect that there are many examples.  If the two readings can wait until they have both the amount of data requested.  This way, they will also have the same number of samples and be better aligned in the text file.

  Your loop will continue to run until you press stop or get an error.

• What is the fastest method producer consumer. Queue, RT-FIFO, event

  Hi all

  Another question completed for the pro:

  I recently inherited the labview code that uses RT-FIFO for the transfer mechanism in the architecture of the producer consumer.

  The code was first written in 3-4 years and is currently in LV8.6. It is possible that the reasons for the architectural decision no longer exists.

  I am qualified using a producer consumer queued architecture,

  I understand the RT-FIFO Architecture.

  I started using an architecture based on events from the user.

  (I have attached samples of each)

  I also see the existence of a priority queue

  Each method has its own capabilities and gaps, that hand, nobody knows the relative performance of each method.

  (Assuming that the only process)

  I would expect RT-FIFO to be faster, there seems to be a version of low characteristic of a standard queue.

  What is the perfornace hit to use a coding user-friendly queue more

  RT-FIFO description talks about commications between the time-critical and lower priority threads.

  Until today, I thought that the queues had the same capacity.

  

  I've included an event method that I commonly use for review by peers and help from other users...

  It allows to:

  1. several producers with different types of data

  2. process 37 production order.

  3 allows asynchronous verification of functional notifiers such as stop, start and abort.

  4. in a system not real-time, it can include interactions of façade.

  What I do not understand on this subject, that's what are overhead or thread priority changes that may occur using this architecture (it solves a lot of problems for me).

  Thanks in advance,

  Hi Timmar,

  Here's a KB article on some frequently asked questions about the RT FIFO: http://digital.ni.com/public.nsf/allkb/7AE7075AF1B2C58486256AED006A029F?OpenDocument

  The more relevant question is #4, I posted below.

  What is the difference between RT FIFO and queues? 
  Functionally, RT FIFO and LabVIEW queues are two pads of first in, first out. However, here are the main differences between them:

  • RT FIFOs run deterministically in LabVIEW and evanescent code queues are not. This comes from the fact that queues use block calls during read/write to the resource shared, while RT FIFOs use non-blocking calls.
  • RT FIFO are fixed size while queues develop when items are added to them.
  • RT FIFOs will execute the code, even if there are input errors. They can (and will) produce new errors and spread the existing errors.
  • Queues work with any type of data, while the data types that can be used with RT FIFOs are limited. Generally any type of data involving allocations of extra memory can be used with RT FIFOs to preserve determinism.

  Let us know if you have persistent questions!

  Ryan

• measure and order through producer/consumer

  Hello people,

  IAM trying to conduct a projekt automated, to test an actuator.

  It must measure signals, process them and also has to create the actuator control signals.

  So far no problem... But it must also operate 3 ditch or several rounds of tests that each has different ControlSignals.

  (example: Test1 - enter: 40VSin (40 Hz), Test2 - entry: Triangle, Test 3 - input: 100Vsin (100 Hz))

  It seems always not difficult enough, but as a beginner of LabView, I m having a lot of trouble to find the right Structure to achieve all this. normally I use SPS systems, but this time to Labview

  Had a few trys a hav downloaded to them.

  But the Structure of producer/consumer makes problems. It does not give all the ProducerLoop signals. :/

  Is there a way to outher Labview programming more effective on this problem?

  4 I'm sorry the bad English

  Greetings

  State machine...

  

• Producer-consumer runs very slowly

  Hello!

  I am currently using a structure of consumption of the producer that is extremely slow and I would like help in how I can speed up.

  A consumer opens a spirit points two façade, these points have a distance which can be increase/decrease with a wheel (connected to LabVIEW via Arduino).

  The problem is this: there's a really (really) delay noticeable from when I turn the knob for moving points (Bonus question: can you do the cover not closed, because I think it's part of the delay (it needs to close and for each iteration)...)

  I read everywhere and saw that many people make consumer a Subvi but I tried it and it did not help.

  I have attached a file (if it helps, its kinda big). I hope someone can help!

  Writing the value property node is EXTREMELY slow.  Change these to use the terminals of the indicators.  You also have a happening a lot in your producer that could potentially slow your descent (hard to tell without the subVIs).

  Why limit your queue only be 1 element?  So, which defeats the purpose of a producer/consumer.  Do not limit the size of your queue and use the normal queue item.

  You also use another loop for data logging.

  Rather than use a Boolean array, it would be easier to understand your code if you have used an Enum in your queue.  Which make the structure more simple case, and you will probably be able to snap to the top of your code to make it more modular.

• Timed loop in loop of producer/consumer

  Hello!

  I have a loop of producer/consumer LabVIEW program configuration to allow me to properly capture the images that are large enough (8MP) at about 14 frames per second (FPS). The program works very well when the consumer loop is a while 'loop' (recorded at 14fps without problem), but I wanted to do a loop timed, so that I can vary the FPS as requires it. A curiosity arises when I do that. Anywhere under 12 fps, the loop works very well and the data is saved correctly. However, when I bump it up to 13fps, the calculated consumer FPS goes haywire and starts to jump between 9 ~ and ~ 13fps (processing of data gets bogged down?). When I set the FPS at 14, the loop runs at a constant maximum 7 fps. Is there something I can do to remedy this situation?

  I have attached my .VI

  Thanks in advance!

  

  Palanski,

  Are you using LabVIEW Real-time? Loops clocked to a windows OS do really increase determinism more than a while loop with a wait until the next timer multiple. Before you change the loop of producer-consumer in order to include a while loop was programming works correctly? You can also vUtiliser the VI analyizer to see how long things take to run. I let the loop of consumer to the producer in the traditional game upward and change the FPS by controlling the timer to wait, after benchmarking your code, it should be done in the same way as you did for the timed loop

• overflow memory for the producer consumer

  I'm trying to save data from 4 ports to 40.96 Mhz. using a producer consumer architecture and a PCIe NI 6527 B using an external clock.

  I inherited code which works for 2 ports.  I tried to add additional ports and changed the size of the data to the DAQ.mx queue and data.  Launch the program several times, reach conflicting error messages after less than 2 seconds from the beginning:

  Error 200284: Some or all of the requested samples are not yet acquired.  [...] To make available samples more quickly, increase your sampling rate

  200361 error: Overflow memory device on board.  Due to the limitations of system and/or the bandwidth of the bus, the driver could not read the device fast enough to follow the flow of the unit.  Reduce your sampling rate.

  What is a race condition between the error messages, a problem of timing of start or something else?

  I approach, how to debug these types of problems?  How can I determine what is causing the error?  I can't single step through because I'm at the wheel of sampling with an external clock.

  Running on labview 2012 Windows XP on the machine who's 3.17 GB of ram.

  Try to reduce the size of your buffer.  In fact, simply leave the calendar DAQmx unwired.  The size of the buffer must be large enough by default.  And then also try to read less data at a time, as data instead of data 500ms 10ms.  What I suspect here, it's that the DAQmx buffer is too large and therefore must use the hard drive for part of the buffer, to slow things down a lot.

  Other notes here:

  1. do not use the time-out to stop your loop of consumer.  Your producer should send an order of a certain type to your consumption by telling it to stop.  In this case, I would use an empty array.  And then, you must release the queue after the loop of the consumer.

  2. you want a constant FALSE to Append Array/String input size of the binary file write.  This will remove the 2 I32s at the beginning of each table that you write.  Eelle are here to tell the size of the table being written.  But since you are just data flow, I doubt that you care about those.

  3. instead of the entire setup of producer/consumer, have you considered using just the DAQmx Configure Logging VI do DAQmx stream directly to a TDMS file for you?  Makes things much faster and much easier on you.

• How to stop an acquisition continues in producer/consumer

  Hello

  I'm trying to use producer/consumer to control 'Start' and 'Stop' to my continuous data acquisition system. I can start the acquisition process successfully, but I can't stop it botton 'Stop '.

  I enclose my simplified VI. Can anyone help to have a look and tell me what is the problem here?

  Thank you

  Bing

  As I said before, use a notification utility and manage the expiration time.  I used a select statement with timeout? Optional Boolean.  If a time-out of events, use the previous value.  If we got a notification, use this value.

  

• Producer consumer with the third loop model

  Hello everyone and thank you for looking at this.

  I have a problem that I thought for a while now on the execution of a third loop in a design model of producer consumer (with events).

  I use this type of model for a UI and am happy with how it works. However if I want to add a continuis loop model to test for example how can I control the loop?

  In my example (see table), I use a local variable to run them (or stop) the test and the same to close the application.

  I don't know why, but this feels wrong to me. Is there a better way?

  Thanks in advance

  Chuck

  Nickelback says:

  Is the problem with the consumer loop only runs when it receives a message from producer loops event.

  Nothing says that you can't have a consumer loop enqueue States to itself.  Of course, this is more in a State Machine in queue with the possibility for another loop to the States of the queue.