disorders of the producer consumer

Similar Questions

• 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).

• Data types in the design for the producer consumer model

  Is it possible for me to use any type of data in a model of design producer consumer, without specifying specific data type?

  what I mean is if there is a way to connect to a data type with which I can use any other type of data, not to mention that one that I have connected, and if not, how can I specify the data type for a number or any other data type, for use in a design of producer-consumer model?

  You can make a part of your cluster of data a Variant.  It will take any type of data.  A common architecture for the producer/consumer is a cluster which is an enum and a Variant.  The enum contains all possible "orders", you might want to send.  The variant contains data that could be of any type.

  Ungroup you in the consumer and get the enum and Variant.  Attach the enum to a case structure.  In the specific case, convert the variant type in a data type of regular LabVIEW and with it as you please.

• Using the producer/consumer with GPIB/VISA model

  Hi all

  So I have a .VI I learned to communicate with my camera, I joined. I tried strip down as much as possible, just to understand the concept. It basically just takes a resource VISA name, use this open VISA, then uses the same resource VISA to write a command that reads the data from my machine (xall?) and then bed in 500 bytes and which prints. If it works, and it's good.

  I try to use producer/consumer model for doing essentially exactly what this guy. I have a RLC, I want to press a button that starts my measure, I want him to taste several times per second, save the data in a text file or .csv and then stop when I press the stop button. Thus, he will be given indefinitely potentially.

  I would like to have the data in a format something like:

  Time C R

  0 5.0 4.3

  ... etc.

  I read the link of model p/c above, but my LabView knowledge is still low. Currently, my plan is to take the part of read/write of my attached VI, which are a sub - VI and then put that in the pink box in the VI for the producer/consumer above page that is labeled "produce data to be placed in the queue":

  

  What prevents me to do this, it's that I can't get the piece of read/write to work properly as a standalone Subvi.

  What is the right way to go about this?

  Thank you!

  I put if you actually found data of your instrument.  Your instrument is not made to take new measures or just send you the last reading, she did.

  Insofar as the file IO, I recommend that you learn to use the palette for the file IO functions.  You need to create your file before your loop, write in a text file inside and then close after the loop.  I don't do the thing the comment on the express VI entry will do what you want.

• Cannot terminate everything in a loop to the producer/consumer

  I have attached a simple vi which was built from the producer/consumer (events) model.  In vi I set up a counter.  I want to be able to complete the meter when you press the stop button.  This does not work as expected.  The meter goes to its full count before the program stops.  The vi works as expected when run in execution to highlight mode.  Cannot understand it.

  Thanks in advance.

  Race condition.  No matter what time something behaves differently with that highlight run it at full speed, and suspect it is a problem of synchronization due to a race condition.

  As soon as your producer loop has the command queued up, she is ready to handle the next event.  If you press the stop button, it is ready to deal quickly and the stem while the ends of the loop and Stop immediately gets back to false.  This probably happens before the loop of consumer has the opportunity to read the local variable of the button stop in the moment, it's true.  Have your consumer while loop redefine the Stop button to false instead ensuring consumer loop has a chance to see if it is true.

  

• Convert single while loop with variable Timing literal to the producer consumer

  I have a controller for a biological system that updates every n minutes or every minute 2n, under certain conditions. My app has a synchronization controller calculates if the current iteration is n or 2n and feeds the output of this calculation in a loop of "Timing" VI in my all. If I understand correctly, this is similar to the issuance of an order of sleep() in a language similar to C and should be avoided. I'm refactoring my code and I heard that they are well suited for this kind of things. Here's how it should work:

  1. Loop begins at the time T, T is saved.
  2. Schedule controller runs and calculates if loop will get minutes 2n or n minutes. This controller will take a number of milliseconds to complete, so we are is more to time T.
  3. Now that the update interval (n or 2n, let's call it u) is known, the loop must until T +u fill.
  4. The PDC is executed, but a number of milliseconds to execute.
  5. The rest of the time until the next iteration of loop should produce the CPU for other processes.

  It sounds to me like it's the kind of a real-time system, although as long as we are in the minute of the original deadline, there will be nothing wrong.

  What the producer-consumer loop would look like? Assumed that the synchronization and the main order controller are separate from the VI.

  
  

• Instead of using the structure of the event with the producer consumer?

  I used the architecture of producer-consumer in the past to control a state machine with the structures of the event.  I'm working now with the basic version of LV that does not include the structure of the event.  Can anyone recommend alternatives to the use of the same architecture in this case?  Thank you, David

  Before the introduction of the structure of the event, the only option was the election.  Control terminals are in a time loop (the producer) with shift registers and a wait, usually about 100ms.  At each iteration of the loop, the control's current value is compared to the previous value.  If it has changed, and then take appropriate action.  Andrey suggested, queues are a good way to pass information between the loops.

  It works for the equivalent of the value change events.  Things like mouse to top or filter events were much more difficult or not possible.

  Lynn

• 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.

• State machine in queue with the producer consumer

  Hello

  I am trying to build a VI where the user allows some Boolean controls on the front panel.
  VI uses a producer consumer in which based on Boolean values clicked architecture.
  some States are queued one recorded in a table.
  After the user is done by selecting, Boolean values should get disabled and the table of States
  should be indexed one after the other.
  It is an attempt to solve the review model car wash.
  However, the VI does not generate the required results.
  Can someone help me please understand what is the correct way to this implementation.

  Thank you

  Its because you have wired the consumer while loop the first stop. Remove and in your loop of consumer, make a comparison of the States that you receive and if it is equal to stop, stop the loop of the consumer.

• Programmatically change the number of producers in an architecture of producer/consumer

  Hi all

  I've got 3 momo SoMat I am streaming of data to 10 Hz. I plan on 3 producer loops and loop a consumer to treat.

  I am pretty sure when I show my customer that they want to increase the number of devices. This scuppers then the producer/consumer model unless I change by programming the number of producers and the rest of the architecture associated.

  Is there a way to do this or a better architecture?

  Phil

  As long as there is an ID any in your command of the queue, I do not see why your consumer cannot handle the producers as much as you need.  I would turn the producer code in a Subvi.  Make sure reentrant Subvi.  Then, you can call dynamically that VI as many times as you need, one for each instrument.

• 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

• Is the reference of the register of necessary shift in architecture of producer/consumer?

  Hi guys,.

  I was just wondering if the producer/consumer architecture is necessary register wired shift to the reference of the queue or the notifier. Is this necessary?

  I think that it isn't, because it's quite a tunnel but could anyone who thinks that the shift register is necessary, explain to me why it is necessary?

  In each of the samples I found the reference to the queue or the Notifier is connected to a shift register, I tried to wire it to a tunnel and it works well, then, what is the best implementation?

  Thank you in advance.

  Thank you guys for your quick responses...

• Buffer could replace the queue in the design of producer/consumer model

  Hello

  I have a question to which the task of buffer to store the data and the queue is also of the same thing so we could use the inplace queue buffer in a design of producer/consumer model.

  No, these examples of buffer not almost equal to a queue, and never "replaces" queue at the producer/consumer.

  The advantage the most important of the queues for the producers/consumers (which none of the other mechanics buffer sharing), it is that it works activities to warn the reader that the data is available. So if you would simply replace the queue by mechanics of tampon too developed that you have attached to your last post, you will lose a large part of the object using producer/consumer.

  Thus, to compare the two mechanics:

  -Tail works activities, while the example of the buffer is not.

  -Tail must allocate memory during execution if several items are written in that corresponding queue. This also applies to the buffer (must be resized).

  -Given that the buffer is actually simply a table with overhead, memory management becomes slow and messy with the increase in fragmentation of memory. Queues to play much better here (but have their limitations, there also).

  -Overload of the buffer (the table manipulation) must be implemented manually. The queue functions encapsulate all the necessary features that you will need. So the queues have a simple API, while the buffer is not.

  -Given that the buffer is simply a table, you will have a hard time sharing the content in two parallel running loops. You will need to implement an additional charge using data value references to manage the buffer or lose a lot of memory using mechanics as variables. Lose the memory, you will probably encounter racing conditions so don't think not even on this subject.

  This led to four '+' for the queue and only a single point where 'buffer' is equal to the queue.

  Hopefully, this clears things up a bit.

  Norbert

• normal priority for the priority producer consumer

  Hello forums or

  I have a question

  Lets say I have a real-time, on the top level vi application I have 2 loops

  1st loop is high priority Subvi, which opened the fpga vi reference, this Initializes the fpga to run with the appropriate settings and after initialization, the actions are read dma fifo data, making digital io and etc, if something is wrong side or the fpga or host side and then it closes in this regard of fpga. This loop has data in it and so the loop of the producer.

  2nd loop is a priority normal Subvi anaylzes and Treaty of the data from the 1st loop, and if something is not it just waits and does nothing. This loop consumes the data by the producer, so it's the consumer.

  My question is that,

  This creates conflicts or problems if it is implemented with the method I suggested?

  Nope. This is how works the producer consumer architecture. The producer must generally specific calendar (acquisition) and the consumer just drags and manages the data when it comes.

• 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.