LabVIEW 8.5 Parallel processing

I am using lv 8.If i use 2 file dialog in the vi.Can i get 2 simultaneous pop or is it still the same ie one at a time in 8.5?

muks wrote:
same is the case when i use a control instead of dialog right?
What do you mean by "same"? What kind of control? can you be a bit more specific? Most users i know can only press one control at any given time, so parallel processing is not that important here. Of course the UI runs in it's own thread, so other things can happen at the same time in the background.
muks wrote:
Then what do you exactly mean by multi threading and parallel processing?
The only person in the thread that mentioned parallel processing was you (in the title) and multithreading was never mentioned here? Are you by any chance referring to a different thread or post with this part of your question?
In any case, LabVIEW was multithreaded way before version 8.0, so you won't see much of a difference going to 8.5 in this respect. Of course there are other nice new features that make upgrading worth it.
What kind of problem are you actually trying to solve?
LabVIEW Champion . Do more with less code and in less time .

Similar Messages

Parallel process in labview

I have an image that i split in 2; left and right, and they both go through the same process of plotting a line. In order to see the process for both images, I have to do parallel processing to see the lines for both left and right graphs.
I put a while loop on both left an right image processes, but i still have the same output. Can someone help me?

As a rule of thumb, copy-paste code is not usually a good thing. Like was stated above, there is not much processing, no need to do it in parallel. I would build the two arrays you have into a 2-d array. Then use an auto indexing for loop with all the identical processing in it. From there you can build your x input and y input arrays for your graph and feed them to your xy graphs. Hopefully this is clear. If you post your code in version 8.5 I can draw it up for you.
CLA, LabVIEW Versions 2010-2013

"Parallel" process

I don't think I ever got this answered..I'm running a functional test (LV2014..Win 7..DAQ6229) In the functional test.vi is a flat seq structure. In each of these seq's is a subvi... subvi1 then subvi2 etc. Each of these subvis I use the DAQ to measure DIO/voltages...etc. to do my UUT testing. Is there a way in ethier the functional test.vi or the subvis to monintor a boolean which stops the functional vi? Just looking for a way to have the DAQ running its thing...running the test ..and monitor a door switch ( the boolean) so that if the user opens the door to the test set it stops the test and turns on a Software LED that I've put on the front panel GUI of functional test. I know how to implement the boolean..I know how to implement the functional tests. I just don't know how to combined them so that they are both running simutaneously.
Thanks..
Solved!
Go to Solution.

There are two questions here. One is "How do I get an immediate response to a change, either to a control or to an instrument reading?", and the other is "How do I synchronize the activities of two parallel processes?"
The first can be handled by an Event structure residing inside a While loop. This is something that patiently "waits" for one or more of the Events it is programmed to recognize. These are typically changes in the value of a Front Panel control, or "signalling changes" to a LabVIEW control or indicator (this means that you change the value in LabVIEW, but "signal" that the value changed).
There are numerous ways to get two parallel processes to exchange information. If you want to control the second process (such as to stop it), you need one or more "points of intervention". Unfortunately, if you have your process-to-be-controlled structured as a long, single sequence, figuring out an intuitive way of "interrupting" it can be tricky.
One thing you can do (given your existing architecture) is to look at each of the sub-processes (which I gather reside in sub-VIs). Is there a point within them that, if you had a "Stop" VI that returned a True value, would cause the sub-process to immediately exit, and that if Stop were true when it started, would again cause it to exit? [This is sometimes called a VI Global or a Functional Global Variable].
If this is the case, write yourself a Stop VI that contains a While loop with an uninitialize Shift Register holding a Boolean value (and initially False, by default). Wire the output to a Boolean Indicator called Stop, with a Boolean input called "Set Stop". Inside, put a Case statement such that if Set Stop is ever True, it sets the Shift Register (and thus Stop) to True.
In your Event structure, if a Stop condition appears, call the Stop VI with True wired to Set Stop. In each of your sub-VIs, call Stop in such a way that if it ever becomes True, the sub-VI exits (doing a safe shutdown, if necessary).
Note that you can have multiple Stop VIs sprinkled around your code, and even within a sub-VI -- you need to find the "vulnerable" points that are accessed sufficiently frequently to allow Stop to have an effect.
I'll leave it to others to discuss restructuring the entire top-level program (a single sequence is not a good way to do this, if for no other reason than it is absolutely inflexible ...).
Bob Schor

Parallel Process Model vs Asynchronous Sequence

I've been studying the features of TestStand, and learning how to use it for about a month, so still very new to the environment (although I have been using Labview and Veristand pretty heavily for about a year). I wanted to get a little clarification on the use of the different process models, because I think I may be misunderstanding some of the terminology.
Here is a little background of my project:
I have a Labview VI that I created to interface with a remote target (emulator). I previously used the VI to run tests manually, and would like to use it as a code module in TestStand so that I can run automated tests. I intend to use the same VI repeatedly throughout the test sequence. The functionality of the system is dependent on maintaining constant communication with the emulator, so I can't be opening and closing the code module repeatedly. Once it is open, it has to stay open and continually communicate (I'm hoping I will not have to create "wrapper" code modules to be the go-between with my current VI). Breaking communication would cause most of the test results to become invalid. For these reasons, I had chosen to call the VI as a code module in a sub sequence so that it can be run asynchronously, outside of the main sequence.
Now, as I learn more about the details of TestStand, I am introduced to the concept of "Process Models". I had initially been using the default Sequential Process model, but would like to know if I should switch to the Parallel Process model. From what I can tell, the parallel process model is used when testing multiple UUTs, or running tests in parallel. Is this correct? To clarify my situation, I will only be testing 1 UUT, I will only be using 1 code module, and I will be running several test steps with that 1 code module. I will need to continually pass data back and forth with the code module as it runs in parallel to the main sequence, and there will likely be several sub sequences called during the process, so that I can maintain modularity with my testing.
So the question is, do I switch to the Parallel Process Model, or should I continue with the Sequential Process Model and the asynchronous sequence to run my code module in parallel? Thanks much.
GSinMN
Solved!
Go to Solution.

Hey GSinMN,
Are you wanting to run your test steps in parallel with each other, or will that need to be a sequential process? The Parallel model is probably not the right choice for this application. The purpose of the Parallel model is to run the same test program on multiple UUT's at once, as you mentioned. Since you are just testing with a single UUT, the best approach would be to run the emulator communication module asynchronously, as you mentioned. You can easily pass data to this code module using a TestStand queue or a similar synchronization object.
Daniel E.
TestStand Product Support Engineer
National Instruments

Parallel process with reentrant VI have same value in both threads

Has it been so long since I programmed LabVIEW that I forgot some basic stuff??
I have a main VI which originally called dynamic processes in parallel.
I then called the sub-vi's dirtectly and still run them in parallel, but thwey now have seperate names.
I use a QSM. Each parallel thread now has it's own QSM, because although I was using a Queue Name for each dynamic queue, the data that was being extracted was shared or done between the two threads. If I confused everyone with the statement, I shall explain.
Two parallel processes, calling a QSM (re-entrant). They have the same number of elements and matching sets.
EX:
Process 1          Process 2
Task1                 Task1
Task2                 Task2
Task3                 Task3
Task4                 Task4
Task5                 Task5
Task6                 Task6
I was expecting each thread (each process) to extract from the queue the list of tasks as entered (from Task1 to Task6). What the processes were getting was the following:
Process 1          Process 2
Task1                 Task1
Task2                 Task3
Task4                 Task5
Task6                 default
Each Process was sending a different Queue Name to the QSM. Each queue should have it's own name.
I need to get this running by tomorrow with no excuse! So I decided to do a lame workaround by also having 2 QSMs. That fixed it..
In each parallel process (which are a copy of each other with different names) there is a call to open a telnet session. I probed and placed breakpoints in the code. Although each process has a different name and the call to the function that opens the telnet session is re-entrant, the very same telnet reference number is assigned to both processes.
Why? Why would they get the same reference number? I made all vi's down to (and including) Telnet Open Connection as re-entrant (although it was not needed) and it still assigns the same reference number to each telnet session. Why? What I am not seeing? What am I missing?
Unfortunately, I cannot post the code.. But it is not complicated code. Just 2 sessions with different IP addresses. I would expect different telnet session references...
As a matter of fact, I need to try something silly..

I should provide more details with the solution....
I just have to stop saying "D'Oh!!"
Okay... here goes...
In the LVOOP, I am using Notifiers and Semaphores to ensure that a race condition cannot occur. Works well with previously written code.
In this particular implementation, I have the same / similar object being created more than once (twice at this time).
Where I went wrong (D'Oh!!!!), was to have a static name for a given object when creating the Notifier and Semaphore references. Since the same name was given, so was the reference. SInce the references were the same, so was the data, and so on.
D'Oh!!!!!!
D'Oh!!!!!!
Now I know why a particular bird was called D'Oh-D'Oh bird...
D'Oh!!! Such a silly mistake...
D'Oh!!!
Hope it makes a few people laugh... or help another bird....

Parallel Process Model Entry

Hello,
First, using LabVIEW 2011 and TestStand 2010 SP1.
We have a custum GUI setup to use the sequential model. At the heart of it, when we hit start, it accesses the Single Pass entry point and runs it with some modifications we've made. Now, we'd like to have a setup that can test multiple DUTs and use the Parallel Process Model. I'd like to have our GUI basically perform the same functions as the built in popup when running the TestUUTs entry point. I've seen the PreUUT callback where you can disable the built in popup. But what I can't seem to figure out is how to initiate a test socket test because it doesn't seem to line up with an entry point necessarily.
When they push the start button next to DUT 0, I want to start socket 0. And if they hit the start button next to DUT 1, I want to start socket 1. What entry point does the GUI use to make this happen? Does the GUI need to start an entry point (IE Test UUTs) then send more information later to start a test? if so, where does TestStand wait for that information within the parallel process model?
Thanks.

One way you could do it is as follows:
Still override PreUUT like in the example and add code which posts a UIMessage synchronously to the UI and then waits for a persocket notification (e.g. you can use the socket index as part of the name to make a per socket notification). Then in your UI, handle the UIMessageEvent on the ApplicationMgr. When you get the UIMessage from your PreUUT you will know it's ready and you can then update your UI to enable the start button, and when the user presses it, you can then Set() the notification to tell the testsocket thread to continue.
for example, in preuut:
Create Notification "MyUIStartNotification Socket 1"
Thread.PostUIMessage(UIMsg_UserMessageBase + 1, RunState.TestSockets.MyIndex, "MyUIStartNotification Socket 1", null, true)
Wait on Notification "MyUIStartNotification Socket 1"
In your UI
Handle UIMsg_UserMessageBase + 1
Enable Start Button
When start button pushed, Set Notification that corresponds to that socket. Pass any data needed with the notification, for example, create a container that contains a serialnumber property and a continuetesting property and pass that with the Set operation. In your PreUUT code get that data from the notification and update your parameters.
Not simple, but doable.
-Doug

Parallel process run independently, but do not stop when vi completes

So I posted a problem yesterday about getting 'elapsed time' express vi to provide updates from a sub-vi to the calling vi. It was suggested that I create a parallel process in the sub-vi that will run the elapsed time function at the same time the other processes are running. I tried to implement this idea, but ran into a problem. The elapsed time process is a While loop paralleled with the main While loop in the sub-vi, It updates every second, based on my time delay, and when I view the running sub-vi, the elapsed time indicator is updating as it should. The calling vi, however, is not seeing these updates. I have wired an indicator to the sub-vi icon, but does not change until the sub-vi finishes.
Also, the other problem with the parallel process is that it runs forever, regardless of the other loop finishing. I have tried to wire an or'd bool to the stop inside the While loop, but when I do that, the elapsed time process does not start.
I have tried data binding a shared variable in the project, and then dragging that to my calling vi, but again I get no updates on the elapsed time.
Any ideas????

A VI must finish looping before it has an available output (the terminal on the sub-vi icon). Research how to communicate between loops. What you are doing can be accomplished with Notifiers (that's what I'd use), Queues, or Global/Shared Variables.
Your issues appear to be due to a lack of understanding of the LabVIEW data-flow paradigm. Check out the Producer / Consumer example. Post code here and see if one of us can give more guidance.
Richard

Parallel process with a queue and file?

Hello, first of all sorry for my bad english^^:
I am working for days on my project where I have to show the parallel process while transfering information by different ways and their problems (like timing and so on).
I chose the transmission of information to a parallel process by (1) a queue, and by (2) a file (.txt). (other ways are welcome, do you have 1-2 other ideas?)
To solve this problem I made three while loops, the first one is the original one, where the original information (as a signal) is created and send by queue and file to the other two while loops, where this information is getting evaluted to create the same signal.
so in the end you can compare all signals, if they are the same - so that you can answer the question with the parallelity of process.
but in my vi file i have some problems:
the version with the queue works pretty fine - it's almost parallel
but the version with file doesn't work parallel, and i have no idea how i can solve it - -
i'm a newbie^^
can someone correct my file, so both (file and queue version) run parallel with the original one, or tell me what i can or must do?
Attachments:
Queue_Data_Parallel_FORUM.vi ‏23 KB

LapLapLap wrote:
Hello, first of all sorry for my bad english^^:
I am working for days on my project where I have to show the parallel process while transfering information by different ways and their problems (like timing and so on).
I chose the transmission of information to a parallel process by (1) a queue, and by (2) a file (.txt). (other ways are welcome, do you have 1-2 other ideas?)
To solve this problem I made three while loops, the first one is the original one, where the original information (as a signal) is created and send by queue and file to the other two while loops, where this information is getting evaluted to create the same signal.
so in the end you can compare all signals, if they are the same - so that you can answer the question with the parallelity of process.
but in my vi file i have some problems:
the version with the queue works pretty fine - it's almost parallel
but the version with file doesn't work parallel, and i have no idea how i can solve it - -
i'm a newbie^^
can someone correct my file, so both (file and queue version) run parallel with the original one, or tell me what i can or must do?
A queue is technically never parallell, though you can have several if you really need parallellism. Other methods include Events, Action Engines, Notifiers (and why not webservices) for information transfer between processes.
Due to limitations in the disk system you can only read/write one file at a time from one process, so i wouldn't recommend that. If you use a ramdisk it might work.
/Y
LabVIEW 8.2 - 2014
"Only dead fish swim downstream" - "My life for Kudos!" - "Dumb people repeat old mistakes - smart ones create new ones."
G# - Free award winning reference based OOP for LV

Parallel Processing : Unable to capture return results using RECIEVE

Hi,
I am using parallel processing in one of my program and it is working fine but I am not able to collect return results using RECIEVE statement.
I am using
CALL FUNCTION <FUNCTION MODULE NAME>
STARTING NEW TASK TASKNAME DESTINATION IN GROUP DEFAULT_GROUP
PERFORMING RETURN_INFO ON END OF TASK
and then in subroutine RETURN_INFO I am using RECEIVE statement.
My RFC is calling another BAPI and doing explicit commit as well.
Any pointer will be of great help.
Regards,
Deepak Bhalla
Message was edited by: Deepak Bhalla
I used the wait command after rfc call and it worked additionally I have used Message switch in Receive statement because RECIEVE statement was returing sy-subrc 2.

Not sure what's going on here. Possibly a corrupt drive? Or the target drive is full?
Try running the imagex command manually from a F8 cmd window (in WinPE)
"\\OCS-MDT\CCBShare$\Tools\X64\imagex.exe" /capture /compress maximum C: "\\OCS-MDT\CCBShare$\Captures\CCB01-8_15_14.wim" "CCB01CDrive" /flags ENTERPRISE
Keith Garner - Principal Consultant [owner] -
http://DeploymentLive.com

Parallel processing of mass data : sy-subrc value is not changed

Hi,
I have used the Parallel processing of mass data using the "Start New Task" . In my function module I am handling the exceptions and finally raise the application specific old exception to be handled in my main report program. Somehow the sy-subrc is not getting changed and always returns 0 even if the expection is raised.
Can anyone help me about the same.
Thanks & Regards,
Nitin

Hi Silky,
I've build a block of code to explain this.
DATA: ls_edgar TYPE zedgar,
        l_task(40).
DELETE FROM zedgar.
COMMIT WORK.
l_task = 'task1'.
ls_edgar-matnr = '123'.
ls_edgar-text = 'qwe'.
CALL FUNCTION 'Z_EDGAR_COMMIT_ROLLBACK' STARTING NEW TASK l_task PERFORMING f_go ON END OF TASK
    EXPORTING
      line = ls_edgar.
l_task = 'task2'.
ls_edgar-matnr = 'abc'.
ls_edgar-text = 'def'.
CALL FUNCTION 'Z_EDGAR_COMMIT_ROLLBACK' STARTING NEW TASK l_task PERFORMING f_go ON END OF TASK
    EXPORTING
      line = ls_edgar.
l_task = 'task3'.
ls_edgar-matnr = '456'.
ls_edgar-text = 'xyz'.
CALL FUNCTION 'Z_EDGAR_COMMIT_ROLLBACK' STARTING NEW TASK l_task PERFORMING f_go ON END OF TASK
    EXPORTING
      line = ls_edgar.
*&      Form f_go
FORM f_go USING p_c TYPE ctype.
RECEIVE RESULTS FROM FUNCTION 'Z_EDGAR_COMMIT_ROLLBACK' EXCEPTIONS err = 2.
IF sy-subrc = 2.
*this won't affect the LUW of the received function
    ROLLBACK WORK.
ELSE.
*this won't affect the LUW of the received function
    COMMIT WORK.
ENDIF.
ENDFORM.                    "f_go
and the function is:
FUNCTION z_edgar_commit_rollback.
*"*"Interface local:
*" IMPORTING
*"     VALUE(LINE) TYPE ZEDGAR
*" EXCEPTIONS
*"      ERR
MODIFY zedgar FROM line.
IF line-matnr CP 'a*'.
*comment raise or rollback/commit to test
*    RAISE err.
    ROLLBACK WORK.
ELSE.
    COMMIT WORK.
ENDIF.
ENDFUNCTION.
ok.
In your main program you have a Logical Unit of Work (LUW), witch consists of an application transaction and is associated with a database transaction. Once you start a new task, your creating an independent LUW, with it's own database transaction.
So if you do a commit or rollback in your function the effect is only on the records your processing in the function.
There is a way to capture the event when this LUW concludes in the main LUW. That is the PERFORMING whatever ON END OF TASK. In there you can get the result of the function but you cannot commit or rollback the LUW from the function since it already have implicitly happened at the conclusion of the funtion. You can test it by correctly comment the code I've supplied.
So, if you want to rollback the LUW of the function you better do it inside it.
I don't think it matches exactly your question, maybe it lead you on the right track. Give me more details if it doesn't.
Hope it helps,
Edgar

Parallel Processing and Capacity Utilization

Dear Guru's,
We have following requirement.
Workcenter A Capacity is 1000.   (Operations are similar)
Workcenter B Capacity is 1500.   (Operations are similar)
Workcenter C Capacity is 2000.   (Operations are similar)
1) For Product A: Production Order Qty is 4500. Can we use all workcenter as a parallel processing through Routing.
2) For Product B: Production Order Qty is 2500. Can we use only W/C A and B as a parallel processing through Routing.
If yes, plz explain how?
Regards,
Rashid Masood

May be you can create a virtual WC VWCA=ABC (connected with a hierarchy with transaction CR22) and another VWCB=A+B and route your products to each VWC

Parallel processing open items (FPO4P)

Hello,
I have a question about transaction FPO4p (parallel processing of open items).
When saving the parameters the following message always appears : "Report cannot be evaluated in parallel". The information details tells that when you use a specific parallel processing object, you also need to use that field to sort on.
I my case I use the object GPART for parallel processing (see tab technical settings). In the tab output control I selected a line layout which is sorted by business partner (GPART). Furthermore no selection options are used.
Does anyone know why the transaction cannot save the parameters and shows the error message specified above. I really don't know what goes wrong.
Thank you in advance.
Regards, Ramon.

Ramon
Apply note 1115456.
Maybe that note can help you
Regards
Arcturus

How to do parallel processing with dynamic internal table

Hi All,
I need to implement parallel processing that involves dynamically created internal tables. I tried doing so using RFC function modules (using starting new task and other such methods) but didn't get success this requires RFC enabled function modules and at the same time RFC enabled function modules do not allow generic data type (STANDARD TABLE) which is needed for passing dynamic internal tables. My exact requirement is as follows:
1. I've large chunk of data in two internal tables, one of them is formed dynamically and hence it's structure is not known at the time of coding.
2. This data has to be processed together to generate another internal table, whose structure is pre-defined. But this data processing is taking very long time as the number of records are close to a million.
3. I need to divide the dynamic internal table into (say) 1000 records each and pass to a function module and submit it to run in another task. Many such tasks will be executed in parallel.
4. The function module running in parallel can insert the processed data into a database table and the main program can access it from there.
Unfortunately, due to the limitation of not allowing generic data types in RFC, I'm unable to do this. Does anyone has any idea how to implement parallel processing using dynamic internal tables in these type of conditions.
Any help will be highly appreciated.
Thanks and regards,
Ashin

try the below code...
DATA: w_subrc TYPE sy-subrc.
DATA: w_infty(5) TYPE c.
data: w_string type string.
FIELD-SYMBOLS: <f1> TYPE table.
FIELD-SYMBOLS: <f1_wa> TYPE ANY.
DATA: ref_tab TYPE REF TO data.
CONCATENATE 'P' infty INTO w_infty.
CREATE DATA ref_tab TYPE STANDARD TABLE OF (w_infty).
ASSIGN ref_tab->* TO <f1>.
* Create dynamic work area
CREATE DATA ref_tab TYPE (w_infty).
ASSIGN ref_tab->* TO <f1_wa>.
IF begda IS INITIAL.
    begda = '18000101'.
ENDIF.
IF endda IS INITIAL.
    endda = '99991231'.
ENDIF.
CALL FUNCTION 'HR_READ_INFOTYPE'
    EXPORTING
      pernr           = pernr
      infty           = infty
      begda           = '18000101'
      endda           = '99991231'
    IMPORTING
      subrc           = w_subrc
    TABLES
      infty_tab       = <f1>
    EXCEPTIONS
      infty_not_found = 1
      OTHERS          = 2.
IF sy-subrc <> 0.
    subrc = w_subrc.
ELSE.
ENDIF.

How to achieve parallel processing in a single request?

Hi all,
I have a method in a Session EJB that will perform some business logic before it returns an answer to the client. The logic it will perform is to collect data from the applications database and two external systems, before sending all data to a third external system to get a response and send it back to the client. Each external system is quite slow so I would like to do all the collecting of data concurrent, parallel processing. How should I handle this? I'm not allowed to create my own threads in EJB's. Can I use MDB in some way? To the calling client this should be a synchronous call...
Greatfull for any suggestions
Cheers
Anders =)

Usually, the request is received by a component located in the web container, such as by an HTTP request (including Web Services). This component is able to start threads to allow parallel processing. Now, if for some reason the request arrives directly at EJB level and that you cannot move its receiver to web component, I think JMS is not a viable solution because you will switch to asynchronous processing and you have no way to make your EJB wait for the responses while preserving the client request (waiting implies programmatic life cycle management, which is forbidden in EJB container). Maybe a resource adapter (JCA) can bring a solution. A resource adapter acts as a datasource (a datasource is a specialization of a resource adapter) and thus it is a logical way to implement an adapter to an external, eventually non-J2EE, resource, as the name implies :) But I don't have enough knowledge in JCA to be sure of this.
Hope it helps.
Bruno Collet
http://www.practicalsoftwarearchitect.com

FORK is Not happening Parallel processing- It's working sequential

Hi,
   we are into PI 7.O and SP 13.
   I am trying to test Parallel processing using Fork step. (With Two branches)
My problem is sxm_moni both branches are not executed simultenously and it's executing one after the other.
Did any body done in XI parallel processing using BPM...both calls has to finish at the same time. I mean first call 10 min and second call aslo has to finish first 10 min ..not other 10 min.
I heard this problem from XI 3.0 and PI 7.O. But PI 7.1 did any body test the Parallel processing using Fork step.
   Pls help me is this issue will resolve if I go to PI 7.1.
Regards,
Venu.

Hi Henrique,
they would not necessarily start at the same time but shouldnt also be queued - Customer expecting the response within a 17 sec or 20 Sec but coming response 34 sec will not ok for the customer..tomorrow need add some more target again 17 sec will take...How PI can handle the Multi threading they are checking...I am not sure this problem fixed in PI 7.1 or not.
there're # of connection restrictions in your system? Check that - Where can I check connections restrictions...If you know pls through some light on this.
Also, how's your BPM transactional behavior (did you flag the create new transaction steps)?
- I did not checked the flag for create new transaction step..once my server is up I can check the flag and I can test.
Regards,
Venu.

LabVIEW 8.5 Parallel processing

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