Using a dynamic event to trigger a signal

Hi,
I'm using a state machines approach to control a motor. I would like to trigger the current (for exemple, when current> 10 A, the event Overload happens). I think it is possible by using a dynamic event but I don't know how to do it.
Does somebody know how to do that?
Thank you

I peeked into my tag cloud- I suspected that one of my "BENex.." tags linked to an example from Ben Raynard on this topic.
Ben posted this example and This link to a Nugget by Ton on dynamic events.
Jeff

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Peculiar problem in dynamic event, which is registering randomly

Hello,
I am using a dynamic event to pass a data (variant) to a vi which i call dynamically. reference of the event is stored in LV2G.
so both main and called vi can access. data when written to the generate user event vi is triggering event at random time when executed.
I am attaching snapshot of the vi which i used to register event.
One interesting thing i noticed is if i put a probe in the error out of the generate user event vi then event will start triggering.
Need help. I am struggling to get a solution.
Regards,
Vibin
Attachments:
Capture.PNG ‏21 KB

Post any code you have on the issue. There may be something simple that will fix the problem. It sounds a lot like a race condition.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Dynamic event multiple loops

I'm trying to see if I can use one Dynamic User Event to control multiple Event Structures. It seems that sometimes once a dynamic event occurs and its "interrupt" is answered by an event case, other VIs only have a short amount of time (<50ms) to reach their event case state for accepting this event otherwise the event seems to be cleared and the other VIs are oblivious that the event even occured.
My Question: Is it possible to use one dynamic event to control multiple Event Structures reliably?
A previous post somewhat speaks of this issue but does not provide a solution or anything insightful.
http://forums.ni.com/ni/board/message?board.id=170&message.id=223495&query.id=135563#M223495
I've included an example of my issue
Attachments:
DynamicUE.zip ‏61 KB

Thanks to both of you. I found the answer to my question in the second posted link. "the common, correct use case is to have one Event structure per dynamic event registration". I tested this out with the previous attachment by registering the User Event refnum from the ESTOP functional global to another Event Registration node. I then ran this refnum to the top loop. (instread of the top loop sharing the registration refnum with the middle loop). Now I can put a delay of 2000+ ms and not even miss an event. cooool. This will probably NOT be my final solution but its good to know in the future.
Most likely I am going to design each of my main VIs to have a main while loop with a User Event Structure listening for dynamic events. Associated with each of these VIs will be a functional global which contains its User Event Refnum and Registration Refnum. This functional global will act as a gateway into the associated VI for other VIs/Subvis to use. This will follow the "one Event structure per dynamic event registration" rule while keeping my API organized and allowing room for scalability by simply adding more functional globals in the future.
Just putting this info out there for other users.
Thanks again,
Craig

How to use the Dynamic register of events in X-controls

Is it possible to handle dynamic events triggering using the X-control and if possible how to handle that option

Yes, it is tricky. I have an idea on the Idea Exchange suggesting that this behaviour is added to XControls - go and give kudos if you agree.
http://forums.ni.com/t5/LabVIEW-Idea-Exchange/Trigger-XControls-for-Dynamic-Events/idi-p/1411062

Using Dynamic Events in PC based RT Target

Hi!
I have a PC based Real-Time Target. I try use dynamic call of VI on RT target with setting reference to user event. My code for Host:
My code for RT Target:
But when VI has started, on user event no action ocсur. How can I use dynamic events on RT Target?
Attachments:
Host.png ‏35 KB
RT_Target.png ‏51 KB

Silentium wrote:
Also i try use Queue in same manner - set reference to queue, but it's not workin too. So i can use only shared variable or TCP/UDP to transfer data between Host and RT target?
You can alos use VI-Server Invoke node Call by reference.
"back in the day..." when LabVIEW Real-Time was new and fresh, Serving an Action Engine on the RT platform allowed all of the threads on the RT target to read and write as they needed while also allowing the access to methods to reading/writting from the PC.
So there are other ways as well (serial, ScramNet....)
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

1043 error when trying to use dynamic events on RT system

Hello,
I am trying to define some dynamic events as specified it the LabView help for RT targets. But when trying to run the vi I get the 1043 error. What am I doing wrong?
Thank you,
Przemek
Attachments:
RT test.vi ‏17 KB

Dear Przemek,
to fully understand you problem and to be able to help you, I will have to ask you a few questions:
What version of LabVIEW are you using?
What RT target are you using?
What specific help file are you referring to?
Are you creating an executable? If yes, this document could be helpful:
http://digital.ni.com/public.nsf/allkb/1E180530E05E4DB28625731C006CCB5A?OpenDocument
Regards,
Mateusz Stokłosa
Applications Engineer
National Instruments

I am using the dynamic signal analyzer.vi but this vi has the output as single precision. How can I change this to DBL precision?

I am using the dynamic signal analyzer.vi but this vi has the output as single precision. How can I change this to DBL precision? If I change the representation from single to double in the AI buffer read.vi labview returns ilegal operation and crash. I have labview 5.1 on windows 95 and one AT-MIO16XE50 DAQ board.
Thanks in advance
Ricardo.

Probably by changing the data type that lvdaq.dll expects to write to is causing the crash. I can't test this since I have only 6.1 installed now. In any case, since the daq card is only 16 bits, the single precision is probably adequate for AI Buffer Read. If you do need the greater precision later on, you should be able to change representation in any one of the upper level VIs.

Want to "ignore previous" ActiveX Event using callback vi/dynamic events in event structure (LV 7.0)

hi there
LV 7.0: i'm using a callback vi with an registered ActiveX event (MSComCtl ToolBar/ButtonClick). i wait for the event with an event structure using dynamic events. how can i wait "ignore previous"? (like i did in LV 6.1 with the "Wait On ActiveX Event.vi").
thx in advance
chris
Best regards
chris
CL(A)Dly bending G-Force with LabVIEW
famous last words: "oh my god, it is full of stars!"

hi sebastian,
here's my code. it uses the ToolBar Control from the MsComCTL. in case you don't have a development license i put an executable to the zip.
i want the event structure to ignore any pending events
(like the old style solution with "Ignore previous" = TRUE).
best regards
chris
Best regards
chris
CL(A)Dly bending G-Force with LabVIEW
famous last words: "oh my god, it is full of stars!"
Attachments:
ActiveX_Events_LV_7.0_(using_MsComCTL-ToolBar).zip ‏234 KB

How can we use CMC / events to trigger a process?

Is there a way we can make CMC / events to trigger a stored procedure or at least a .exe file?
how?

There's a starter on events here:
http://scn.sap.com/community/bi-platform/blog/2013/01/07/cmcevents-in-business-objects-and-its-usage
Not sure exactly of your workflow, but you can also schedule a custom program object and schedule that to run based on your own timelines.
http://scn.sap.com/docs/DOC-40837

How to use a SubVI as a trigger for main VI?

I'm working on my main program now, which calls the two SubVI's (x and
y galvo). The program is essential a data acquistion program that acts as an oscilloscope that saves multiple records of data. I have been triggering off of a function generator (Tek AFG), so I just had to select that channel in the program. However, now I am replacing the function generator that triggered the Tek AFG with the PCIe-6321. Is there a way I could trigger off the SubVI(s) that control the 6321? I attached the program.
Thank you,
Ryan

I would use a Producer-Consumer archetecture. If the fp is something that will be accessed frequently, consider using an Event structure; otherwise, use your sub-VI to trigger the event you wish to start. Yes, you can use your sub-VI to trigger an event in your main program (P-C data or event type). There are many ways to do it. What type of signal are you trying to measure? Do you want it to trigger on a certain condition/measurement?
Reese, (former CLAD, future CLD)
Some people call me the Space Cowboy!
Some call me the gangster of love.
Some people call me MoReese!
...I'm right here baby, right here, right here, right here at home

Smartforms, how to use control break events

Please help with this requirement.
Purchase Docu No.111
Pur Item No       Mat no       Quantity
1                        2356      2000
2                     1256      2000
3                     8556      2000
Purchase Docu No.112
Pur Item No    Mat no    Quantity
1                      9656      2000
2                      7356      2000
3                      1356      2000
Purchase Docu No.113
Pur Item No    Mat no    Quantity
1                      5356      2000
2                      8356      2000
This i have to design for the smartform.
1 header data then its item data.
like is Script i can call the WIndow elements using control break events in the driver prog but how to get this kind of output in Smartforms.???????
Thanks

I dont want trigger new page.
In the same page i want like this
I have purchase docu data in only 1 internal table.
So, for every new VBELN, under this i want its corresponding item details.
I have created the command node for the main window with 2 rows, in the 1st row i am giving VBELN and in the 2nd row i am giving in item details like item no, matnr etc etc and in the condition its askng Field name and Comparison Value.
How shold i give condition.??????
Thanks
Edited by: Jalaaluddin Syed on May 1, 2008 5:03 PM

Paging issues using a dynamic view object...

I am working on an application that uses JAG to generate JSP pages, i had the requirement to use dynamic view objects where the view object query is generated at runtime. The rest of the application is more or less the same... I used the defult functionality provided by TableScrollButtons.jsp file for paging. Now the problem im facing is that while the '>' and '<' buttons are working fine, i cant seem to navigate to the pages using the drop down...
With the default handler, whenever i select the range the range displayed remains the same ie 1-10, 10 being the rangesize, but the rows are refreshed with values from the next page. Also, if the next page is the last and is incomplete, then the rows are pushed in from the bottom, so that the last page is always full...I tried the tuning panel in the view object edit dialogue and all settings are fine (i think)...could anyone please tell me what i am doing wrong??

could it be because i am using a dynamic view object with dynamic bindings? i am using the preparemodel() method in the action as follows...
protected void prepareModel(DataActionContext ctx) throws Exception {
inferRangeBindingIfUnset(ctx);
ctx.getBindingContainer().setEnableTokenValidation(false);
String sql = ctx.getHttpServletRequest().getParameter("sql");
String cost=ctx.getHttpServletRequest().getParameter("CostCostCent");
String event=ctx.getHttpServletRequest().getParameter("event");
if (sql != null && event == null) {
setupDynamicQueryAndDynamicBindings(ctx,sql.substring(1),cost);
if (retrieveOnlyCurrentPageFromDatabase()) {
ViewObject vo = getIterForPaging(ctx).getViewObject();
if (vo.getAccessMode() != ViewObject.RANGE_PAGING) {
vo.setAccessMode(ViewObject.RANGE_PAGING);
// if(event==null)
super.prepareModel(ctx);
ctx.getBindingContainer().setEnableTokenValidation(true);
if (ctx.getEvents() == null || ctx.getEvents().size() ==0) {
setPage(ctx,1);
setLastPage(ctx,getIterForPaging(ctx).getRowSetIterator().getEstimatedRangePageCount());
else if(event.equals("setRangeStart")) {
setPageFromRequest(ctx);
}

Resetting a variable in an event structure (dynamic event)

I'm working on moving an event structure into a sub VI. This means I have to register dynamic events.
The event structure is handling some button clicks. The state of the button (mechanical action = latch when released) resets itself automatically as long as the variable is placed within the value change case. Leaving the button in this case is not possible when the event structure is put in a sub VI and the variable is located in the parent VI. How do I make sure the button unlatches after clicking on it? I have attached an example where all the code is in one VI (the local variable must be moved outside the event structure in order for it to be moved into a sub VI). Any ideas?
If you open the VI and run it, you can click Start which will cause the counter to start incrementing. The button only unlatches as long as the variable is located in the value change case.
(Btw, how do you put images inline in a post?)
Rob
LV2011,LV2012,LV2013
Attachments:
img.png ‏18 KB
main.vi ‏17 KB

Race conditions are the primary reason not to do that. But since your treating your variable as a latch, I doubt your using the value you read from it anywhere, and in that case it can't create a race condition. There's also the possibility that the control's reference could become invalid. But since this is a sub VI of the control's VI that can't happen (even if it could you can check the error out of the value property node to see when it happens and deal with it).
I'm not sure about the flickering, Since I can't seem to duplicate it with a simple test case on my machine. It might related to whatever else you're doing in the event apart from reseting the value to false.

Are you ever required to wire the dynamic event terminals through an event case?

I remember some time ago, I ran into an issue while using an event case where my program was not functioning properly until, on a whim, I wired the dynamic event through that event case... now the reason I'm asking this in a general sense is because I don't remember what particular code I had this issue with and I could have been failing to update a shift register or something.
In code I'm currently writing, I'm simply passing the dynamic event wire in a shift reg. I was just wondering if there's any difference between wiring it through the event cases or simply passing it to the output shift register (without passing through the event cases)...
any info appreciated!
Thx
-pat

You do not have to wire it through. You don't need a shift register for references since the value will be the same for each iteration. In fact using a shift register is probably what caused issues. You probably updated it with the default value somewhere.
=====================
LabVIEW 2012

Tag engine dynamic events

Does anyone have an example using dynamic events with tag values from the DSC engine?? I use 7.0 format.

hi there
you can combine DataSocket Read - function with timeout and a registered user event (see attachment)
Best regards
chris
CL(A)Dly bending G-Force with LabVIEW
famous last words: "oh my god, it is full of stars!"
Attachments:
Wait for Tag to change ist value_7.1.vi ‏74 KB

Using a dynamic event to trigger a signal

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