Event structure problem in updating array

Hi, i have a problem with my .vi...
i have an array of 10 boolean i want to modify by pressing SET TRUE or SET FALSE buttons, after selecting (with the ring selector) which is the elemente that should be changed...
there seems to be something strange in the behaviour... the array is not correctly updated... maybe there a big mistake i cannot find...
i hope you could help me
tks
Attachments:
array_modify.vi ‏18 KB

The problem is the the Ring control is read before the event structure, so it return "old" data when you click of either SET TRUE or SET FALSE.
You need to move it so that it is read inside the event structure after you click on one of the "SET" buttons.
Create a local of the Ring for one of the SET events and move the Ring terminal into the other.
Or create a blank event for the Ring control so that it will update the input tunnel going into the event structure.
Or create a single event to handle both SET TRUE and SET FALSE.
Omar
Attachments:
array_modify.vi ‏9 KB

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Stuck with making my event structure examine if two arrays are equal

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My program is attached.. It is eventually going to be a memory game when I get it working..
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Attachments:
attempt 2.vi ‏18 KB

Seems to me like you should implement a true State Machine. This way you can repeat states and/or jump states as needed.
State Machine
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Unofficial Forum Rules and Guidelines

Event structure problem

HI!
I am a Labview Newbie and i have some problems with my event structure in the program "Biegelinie"! I get always failure from the event-structure in the failure-list!
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Attachments:
program.zip ‏134 KB

For a less complicated system, you can achieve nearly the same
functionality without using an event structure. Simply poll the
state of the booleans you require and feed them into case
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Message Edited by shoneill on 07-25-2005 11:30 AM
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Attachments:
Polling boolean.vi ‏23 KB

Event Structure Problems

Hello all,
Im using the following code trying to obtain voltages and then use the peak voltage to trigger an event. My event structure doesn't seem to be working properly and I'm not sure what I need to do.
Take a look, and any help would be great!
Attachments:
Untitled 5.vi ‏43 KB

hey,
there are a couple of things wrong with your layout, other than the Event Structure isn't being called. What you have here doesn't do a lot and that is the beauty of LabVIEW: you can do the same thing in many different ways.
Following the Event Structure design you are intending to go with I have attached a redesign of your code, including comments. I believe this should work for you now. I have followed the common State Machine approach, which quite nicely, uses the Event Structure - when in a 'stable' or non-working state.
The main aspect you need to consider is how the Event Structure is called. It needs an interrupt in order to identify a state that it needs to address. In this case here, to increment a counter each time the peak voltage is detected.
The Enumerated data type (the value that holds the state of the State Diagram) can be added to or changed. Normally you should 'Customize...' the data type (right click) and create a Type Def variable (ensures all changes are provided throughout the code, where it is used).
There is more you can do with this structure, it is quite useful and powerful. There are quite a few examples online or within the LabVIEW help function to give you more. In regards to the DAQmx, there is a State Machine project already set up for you - with all type-defs and some events already created for you. After you've mastered this you should go along and check that out more.
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Attachments:
Untitled 5.vi ‏25 KB

Updating array data in sql database

HI,
Im facing problems in updating array data in SQL database.
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Hi Pavitra,
I'm not very clear on how you have inserted the data into your application, but I do know that when you call the UPDATETEXT or WRITETEXT function you use the TEXTPOINTERS to point to the first location of a 1d array. So, depending on how you've stored the data, you may have problems updating your data if you're looking at it as a 1d array instead of how you originally formatted it. If you are able to successfully access the data as a 1d array, you can use the database variant to data type vi and pass in a string array constant for the data type. This will convert the variant datatype into whatever you specify. You may have to index the row and column of the variant (you receive a 2d array of variant) first before you convert. If possible, can yo
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National Instruments
Jeremy L.
National Instruments

Using Event Structures with Array of Clusters

Using LabVIEW 8.5
Hi all,
I'm trying to convert an existing application to one that can be used
through a touch screen. I updated the UI and added an event structure
to listen for mouse ups on controls that require a HMI keyboard or
numpad to show up. Although I've been programming for a while, I'm new
to LabVIEW and am struggling with a problem:
Is there any way to have an event case listen to an event within
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HMI keyboard or numpad and send the text to that cluster. In my watered down app (Array of Clusters.vi), I've put 3 arrays of clusters and a few stand-alone controls to give you guys an idea of what I'm taking about.
BTW, I'm using the HMI Keyboard and Numpad built by the Beta Community (http://decibel.ni.com/content/docs/DOC-1062) and modified it to add a "Clear" button to the keyboard and numpad. Please let me know if I implemented this in the best way.
Thanks for the help,
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Message Edited by bhatiak on 08-04-2008 03:55 PM
Attachments:
Array of Clusters4.llb ‏274 KB

My old tic tac toe example shows how to determine which square of a 2D array has been clicked.
http://forums.ni.com/ni/board/message?board.id=170&view=by_date_ascending&message.id=247044#M247044
You probably can adapt some of it for the arrays on the right. If the array can be scrolled, you also need to account for the "indexvals" offset.
The Layers controls is easiest, because you only show one element. Just read the "index vals" property to get the array element and parse the coordinates to get the cluster element.
btw: the small while loop on the right serves no purpose at all and acts just as a CPU burner. You can delete it without any change in functionality. Is there anything else to it?
LabVIEW Champion . Do more with less code and in less time .

Array of buttons and Event Structure

I have a the same problem... I was wondering if you were able to find a soln.
I have literally thousands of buttons and each button as a unique key code and unique name.
For Example :
Button Name    – Key code #
PUSH              - 1
POP                 - 2
PULL               - 3
The way I program this simple algorithm is deadly painful.
1)      I create 1000 buttons by going to control->buttons.
2)      Then I have to go through one by one to change the Boolean text to “PUSH,POP,PULL…”
3)      Then used the Event Structure, adding in all the controls names “PUSH, POP, PULL..” In side each event, I placed the key codes “1,2,3..”
I have search and tried for weeks to find a better way, and still nothing comes to mind.
Please help.

Hi Ben,
Thank you for your reply, I have attached my try_code and a picture of the code I currently have.  I am new in Labview, but I am confident that, there must be a easier way to make an array of buttons with different button name and an associated number to that button.
The 1st file, is to show you want I am currently doing, (painful)
The 2nd file attached is some of the things i tried, I had great hope with my try_code, array_jan25. But I couldn't get it. I think I am very close.
Thanks again,
Attachments:
ThePainfulWay.doc ‏63 KB
Array_jan25.vi ‏42 KB

Problems using event structure to write new parameter values to VISA

Attachments:
FMA_event_2.vi ‏28 KB
FMA_event_2.vi ‏28 KB

It seems I'm also having trouble using forums..not sure what happened...updated and corrected thread: http://forums.ni.com/t5/LabVIEW/Problems-using-event-structure-to-write-new-parameter-values-to/td-p...

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I am doing some testing with dynamically registered events. For these testing purposes, I have 2 separate arrays of boolean references hooked up to the dynamic input terminal. The event structure is executing like I expect it to. The only problem is that I want to know the index within the array for the event that triggered the value change event. I would have thought I could use the CtlRef node to determine this, but instead it returns a reference to the actual boolean control that triggered the event.
I could write a subroutine that searches for the label of the boolean that triggered the event within the arrays, but that is not efficient or good practice.
So for instance, if I click on Boolean 2, I'd want the event structure to know it was array #1, index 1. If I click on Boolean 6, I'd want the event structure to know it was array #2, index 2.
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That is a very good idea. The caption is good to use for the label you show to the user. You can change it to show different things, even programmatically, such as if you need to make your application more international and have it display controls in different languages to different users. It lets you use longer or more descriptive names, without having those long names eat up block diagram space.
Another thing I've done is take the control reference and search for it among the array of control ireference. Search 1-D array will give you the index of the control within the array. Then I can use that index and apply it to a different array and index out a value from that. It could be a name, or perhaps a numeric value I use as a multiplier or something like that. Just make sure there is a one to one correlation between the references in the array and whatever is the other array you are getting additional data from. For what you have drawn now, it could be a little bit complicated because you actually have two different 1-D arrays of references. But if you concatenated those arrays together, you'd have a single 1-D array you can search.

Event Structure: update the structure with a tab control

Hi!
I want to be able to update the code contained within an event structure by a tab control value change, in addition to the usual bool controller in the UI.
The problem is that the event structure don't seem to run when the bool has a value change for the tab control. I have made a short .vi to demonstrate. A counter is placed in the Event structure so it is possible to see if it is running or not.
Any ideas?
Best regards
Is my avatar the dog from the fraggle rock?
Attachments:
forum_question.vi ‏12 KB

Here is a version of your code using a Value Signaling property node.
I "think" it does what you want ...
steve
Help the forum when you get help. Click the "Solution?" icon on the reply that answers your
question. Give "Kudos" to replies that help.
Attachments:
forum_question_mod 2009.vi ‏15 KB

I need help with event structure. I am trying to feed the index of the array, the index can vary from 0 to 7. Based on the logic ouput of a comparison, the index buffer should increment ?

I need help with event structure.
I am trying to feed the index of the array, the index number can vary from 0 to 7.
Based on the logic ouput of a comparison, the index buffer should increment
or decrement every time the output of comparsion changes(event change). I guess I need to use event structure?
(My event code doesn't execute when there is an event at its input /comparator changes its boolean state.
Anyone coded on similar lines? Any ideas appreciated.
Thanks in advance!

You don't need an Event Structure, a simple State Machine would be more appropriate.
There are many examples of State Machines within this forum.
RayR

Event structure to detect value change of a control within a cluster in an array

I have 1D array that contains a cluster. The cluster contains a numeric and a boolean control.
If the user starts to edit the numeric control value i would like to call one subVI, and if the boolean control value is changed, call a different subVI.
The array control on the front panel allows the user to edit a number of the array elements.
I would like to use an event structure to detect a value change in the cluster. When editing the Events, in the Event Sources panel i get the option to select only the array, not the cluster within the array or the controls within the cluster. Can the Event structure be opened up to show controls within clusters and arrays?
The solution i am using is to detect a mouse up event on the array and then use property nodes to determine if the key focus is on the numeric, and a case structure to determine which subVI to call. This works, but is there a better (simpler) way?
Thanks, Blue.

Thanks for the responses guys.
The tricky bit was that i wanted the numeric control values to flag they were going to be edited, so i could call a subVI, before their values were changed by the user. This is done by using the key focus property node, - i need to detect changes on the fly rather than post the event. Probably didn't make this clear enough in my original post.
The array is of variable size depending on if the user decides to insert or delete elements. The user also has the option to click and edit the array without having to do to much scrolling through the array index, as the FP shows several elements at a time. The Event Structure does a good job of automatically determining which element in the array is being edited, and returning those values to the property nodes. Turned out simpler than i thought it might be at one point!
Cheers, Blue.
Message Edited by BlueTwo on 01-15-2009 06:52 AM
Attachments:
evstrct1.jpg ‏63 KB

Event Structure's value change, not detecting changes when tabbing thru array of clusters

Hi! I have an array of clusters (int, int, string, int) control, and want to detecting changes made to the it. I used the Event Structure's value change case on the array, it works excellent except that it'll only detect the changes when you click out of the element or press the enter key (the one by the numbers, not carriage return). I want it to detect the changes when I tab thru the cluster or array too, but I can't figure it out... Does anyone have any ideas?
Thanks!

mfitzsimons wrote:
altenbach
Tried Value Change with my example done in 7.1 and it doesn't trgger an event. That is why I suggested Mouse Down.
Curious. I did a few minor edits in 8.0 before saving as 7.1, but the simple value change event got triggered just fine when the value vas terminated with a tab in 7.1. Every time. Strange....
Are you on 7.1 or 7.1.1? Maybe there's a difference (I am using 7.1.1).
LabVIEW Champion . Do more with less code and in less time .

Strange problems about my projects(efficiency,event structure,queue)

hey,guys,i am a labview user from china,so forgive me about the chinese words of my projest. i found something wrong with my work. .
there are two functions in my "While loop", the first one depends on "queue" and is to get information from UART, the second one is "event structure" to send information through UART. my problems:
1. i can not stop while loop by pressing "停止“, and i find two ways to stop it. first, i press"停止”,then, i press any buttons that can trigger "event structure"twice, at last, while loop can stop.the second way, i press buttons for "event structure" one time, then "停止”， and then the same button for"event". it also works
2.my work does not run efficiently. you guys can try. once you press buttons for "event structure", it responses very slowly,and if you press many times,the whole program seems like suspending.i have added a LED named test at the front panel, it should light once you press "运行“. and it also shows how slow the whole program is.
i have attached my work, and my main vi is "串口通信主VI".
can any body give me some suggestions? thanks a lot
Attachments:
Uart.zip ‏140 KB

Your event structure will execute exactly once per loop of the main loop, thus the other three loops must stop before handlig the next event. You will also get a race condition between the top loop and the events when writing.
I'd put the top loop as the timeout case in the event and place the loop around the event for starters.
/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

Problems closing several loops in a state machine with an event structure

I am having some problems closing three loops running in parallel in a state machine. I have one loop for an event structure to monitor user controls to change the state. The other loop is the state machine which will control an actuator, and the third loop is for data aquisition/analysis. I want to be able to hit the stop button and go to a "shutdown" state where I can home the actuator then close the loops and finally go to the last "shutdown" subdiagriam in the flat sequence structure. Currently when hitting the stop button it goes into the shutdown state and will end the state machine loop but it appears the other loops are not closing until I hit the stop button again. Could this be due to using a local variable for the boolean to control the loop conditions? I attached a screenshot of the block diagram. Any advice would be great!
Attachments:
example.png ‏108 KB

You have a classic race condition due to overuse of local variables. If the stop event fires in the upper loop, the local variable connected to the loop termination condition has already been read (it is false!). This means that the upper loop will iterate once more and again wait at the event structure for the next event. At this time, the local variable connected to the loop termination is TRUE, but the loop cannot complete until the event fires again, for example if you press the stop button once more.
The correct way is to connect the terminal of the stop button across the right event frame directly to the loop termination terminal. Now it will get the TRUE value correctly once the stop event fires for the first time.
LabVIEW does not execute left to right, execution order is determined by the wiring.
I also agree with the above message that you should rethink and re-architect your code using established coding guidelines.
LabVIEW Champion . Do more with less code and in less time .

Event structure problem in updating array

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