Which situations give an event structure do not capture a Boolean value changes?

Similar Questions

• Cases of event structure do not work (probably façade is disabled

  Please find the attached VI, I tried the update feature and inlcude a new code. And it ends in a non-responsive event structure.

  Is this a bug (related to the definition of property of "Windows run in a transparent manner") or am I missing something...?

  You have your events to lock the front until full.  If you have a keydown event, the structure of the event 2nd he also captures and locks the front panel.  You might think that you have a timeout, but this loop does not receive the value of timeout until the first so that the loop ends.  Your second loop depends on the completion of the first loop.

  If you do not hit the combination just with a keydown event (or leave of mouse or mouse enter and other events that would lock the front) which causes also this first loop to stop.  You have locked your program.

  As Mike said, have 2 structures of event on a diagram when you do not understand how to work the event structures.

  I recommend reading warnings and recommendations when using events in LabVIEW.    This document has a little more items that I think should be mentioned.  But it's a good start.

• Reach target FIFO in the event structure will not achieve

  Hello

  I'm just counting the time in ticks between edges mounted on two digital channels. Therefore, I use a myRIO and LabVIEW 2013 SP1 on a Windows 7 PC.

  As you can see in the attached photo, I use a FIFO extended target to switch the number of ticks between two SCTLs events to a while loop, where I want to send them via DMA to host of the RT.

  I chose this model to limit the number of DMA channel and increase the SCTLs clock (allows greater accuracy in time). The number of ticks is determined using the DSP 32 bit - built-in counter.

  However, when I run the VI no data is written to the target FIFOs scope. 'Number of elements to write' is still 127 (128 requestet), 'Number of items to read' is always zero. "ch0 post" indicates that the "real" State of the structure of the case is actually entered.

  Edit: all indicators have been added for debugging purposes. Simulation on PC indicates no error either, but I realized that no data is written to the host of RT during actual use.

  I checked the cRIO programmers guide and the high Performace FPGA Developer's Guide and do not see where I was wrong. However, it will not work.

  I would be happy if someone could help me solve this problem!

  In the lower part while loop what do you do if one of the read FIFO has expired (zero cases in the structure of the case)?

  If you set the Boolean value False in any other case (1.3) then you'll only send something to the host when the two data FIFOs received in the same loop iteration.

  If she receives a number of cycles on a FIFO in an iteration, and a number of cycles on the other FIFO in the next iteration has expired will never be null.

  To debug you may store the value 'tick count ch0 fifo' in a shift register and update only when the delta_c_ch0 FIFO does not time-out. Then you can see if this value is always nonzero.

• The VI call does not show correct Boolean value returned from Subvi

  I have a Subvi, which returns a Boolean to indicate whether the system is WoW64 or not. When I run this by herself or with a probe VI, I get a TRUE result (my OS is 64-bit Win8, and I am running 32-bit LV2015).  When the VI is called as a Subvi, and the output is wired to a Boolean value on the front of the caller, the value is FALSE, even if it is TRUE inside the Subvi.  The LV2014 code is attached below.  It happens in 2014 but not 2013.  Is there something to do with DLL calls made by the Subvi which is corrupting the Subvi call?

  
  

• Object that can be bound but not updated when the value changes

  I have an object that is declared as [Bindable], which is updated in a component that is also declared as [Bindable] However, when the value is changed the user interface shows the change but the linked object never gets updated.
  
  Are there cases where related objects do not updated?

  Yes, as I said, pass the name of the property and the value in the change manager.

  Support rating allows you to set the value, not a switch statement. Some examples of code.

  Tracy

• Why my event structure reacts to an event of "change value"?

  Hello

  I created a VI with 2 while loops and structure 1 integrated event. The first while loop creates a square wave and the value of the pass signal periodically - this event is registered by a property node and also shown on an indicator. I've linked the second event called "Mode-number: changed value" so that the signal and tried in various ways to "activate" the structure of the event (I tried to use event dynamic registration, property nodes, event tool etc.

  Attached to this message is a png of the VI file.

  No idea what could be the problem?

  Thanks much :-)

  Bruno

  You must use "user events. You should also look at some of the examples/tutorials on how to use them, see here: http://zone.ni.com/reference/en-XX/help/371361K-01/lvhowto/creating_user_events/

  What you have done is to try to enter a value in both structures change event - this is not actually generate a value change event. Value change events are generated when you (as a user) change a value of a control on the front panel.

  Alternatively, you can use the 'Value (signalling)' property that will allow you to update the value of an indicator and also generate the event changes its value. I think in your case if you are better to use user events.

• Event Structure Weirdness

  Last night, SAP posted an interesting question on his blog (The Daily CLAD).

  In short, we create a dynamic event, enter it and generate two events with the data being 1 and 2.  Then we travel a structure of the event that is registered for the dynamic event.  Inside of the event is another structure of event which is also on the dynamic event inside a loop set FOR to run twice.  The data of the event was autoindexed and went straight to the final output.  Now logic would state that the output should be {1,2}.  But when I run it, I get {1,1}.  I thought it was really strange.  So of course, I got to play.

  I changed the buckle FOR to run 3 times.  Oh, it is here and waiting for another event.  If it is to see two events, as it should be.  It's just that for the second event data is not transmitted correctly.

  But let's play others.  I put another LOOP around the external event structure and did run twice.  He does not see the second event at all (that is to say, is there and waiting for another event on the second iteration).  Why not?  It is registered for it?  He saw the first event?  Why wouldn't it the second event in its queue?

  Now if I remove the inside OF the loop and let my loop FOR external, everything works perfectly as I expect.

  Now, it becomes even more strange.  I added a button and changing the value for the button of my external event structure (the two structures event with loops to go twice).  The structure of the external event is also ignorant of my button value change event.

  OR, what the #* $& @* is happening here?

  The problem is not with nested structures event, but with the shared record refnum. An event record refnum should belong only to a single event structure. As soon as share you, you get undefined behavior. It could work very well, he might behave in a totally random way.

  Example of David is wrong for the same reason. He may have worked when he ran, but it is not something that must be invoked. The structure of substantive event should have a separate record node.

• Structure of the event - controlled motor not variable

  I have a state machine that includes certain structures of the event. These event structures are used to control stepper motors using an Arduino Mega microcontroller. I'm using labview in 2012.

  The entrance to one of the events is the variable "pour the entry. I want to use it to control the motor speed and direction.

  If I control the motor as shown in the attached image Working.jpg, then the motor functions correctly. If I fix the motor to the steps variable # then the engine moves at the speed set in the right direction depending on whether the entry "pour" is positive or negative.

  However, I want to control the speed of the engine, not the number of steps, with the variable "pay Input". I checked that the values read by the indicator image INPUT_VALUE works do not are of the same order as the specified values, working, by using the "Set Speed". When I connect the value of the entry to the spindle speed of the motors of the Arduino (not_working.jpg) icon, the engine is running, apparently indefinitely at maximum speed. I don't understand why there is a difference in motor behavior between the value provided by these two methods at the entrance to the speed of the motor. I am confused by the present and don't know where to go from here.

  The structure of the event somehow behaves differently when taking a value from outside the structure to this data inside? or y at - it something to do with the opening of the structure on its first loop?

  I have also attached my vi together, even though she may not be the easiest to follow and requires an arduino Mega to run.

  Carlr wrote:

  I have a state machine that includes certain structures of the event. These event structures are used to control stepper motors using an Arduino Mega microcontroller. I'm using labview in 2012.

  The entrance to one of the events is the variable "pour the entry. I want to use it to control the motor speed and direction.

  If I control the motor as shown in the attached image Working.jpg, then the motor functions correctly. If I fix the motor to the steps variable # then the engine moves at the speed set in the right direction depending on whether the entry "pour" is positive or negative.

  However, I want to control the speed of the engine, not the number of steps, with the variable "pay Input". I checked that the values read by the indicator image INPUT_VALUE works do not are of the same order as the specified values, working, by using the "Set Speed". When I connect the value of the entry to the spindle speed of the motors of the Arduino (not_working.jpg) icon, the engine is running, apparently indefinitely at maximum speed. I don't understand why there is a difference in motor behavior between the value provided by these two methods at the entrance to the speed of the motor. I am confused by the present and don't know where to go from here.

  The structure of the event somehow behaves differently when taking a value from outside the structure to this data inside? or y at - it something to do with the opening of the structure on its first loop?

  I have also attached my vi together, even though she may not be the easiest to follow and requires an arduino Mega to run.

  You have a very inappropriate design of "state machine" - even if you do not have same event in more than one of your structures of the event (in addition to time-out), looks that get some of your treatment to go forward until you get something very specific (and in which none of your other user events are being processed).

  I strongly suggest that first set you design of State machine - perhaps follow producer/consumer Design Pattern (events) rather than having everything in a loop, the way you have.  If you keep everything in a loop, you should consider redesign so that you at least allow events to deal with rather than stay in a loop for an indefinite period!

  In any case, in the case where work, you send variable "Set Speed (steps per second)" for engines step by step write vi.  But otherwise, you're feeding 'Entry for' value - are they the same? And to let you know, you send only command "write" step by step when the input value to be paid.

  It's a big mess!  For starters, look at the attached picture, get rid of your structure of the event that has "for the entry" and replace it with what I showed in the picture. (In fact, all your event structures can / must be replaced with a similar logic.) Does not need the event structure in all this, you're just more complicated it must be!

  -DP

  

• Button value change records in the structure of the event, but does not change appeaance?

  Hello world

  A quick question... I hope someone can answer...

  I have a code that uses a PS button within a structure of event to trigger a signal of AO... My code is below. The code works fine and the OD goes off when you press the button E-Stim... But when pushed the button does not change with reliability the appearance (i.e. of the gray 'off' red 'on' color)... Sometimes color changes; no other time not... If I remove the structure of the event and the survey button in the appearance changes as expected.

  What is going on? I would like the button to change the colors on the user interface to indicate that it works... Should I programmatically control the color?

  Kind regards

  Jack

  

  I guess that when query you the button you have some delay in your loop? Locking means that the button will change its value when you press it, then switch back to the original value once the value of the control has been used by the code. When you ask, this means that until he reaches the next iteration of the loop, but in the case where the structure that will happen immediately.

  The default setting for the buttons to modify its behavior as in most of the application would be latch releasing. You then raise the event when the button of the mouse over the control. This also allows "drag" control if you push down on the subject, given that you do not release control in this case.

• structure of the event recorded does not change value

  I have a VI that communicates with an FPGA via a telnet interface.  I have several Boolean controls on the front panel.  When you click a control, it sends a write command on the face i in telnet to the FPGA.  Similarly, if a process in the FPGA himself wrote the same registry (that control written when I clicked on it), an order is generated in the FPGA and returned to the VI and the control (via a local variable) lights or unlights accordingly (based on value).  In other words, these controls are read-write...

  It's all workers, except for one important thing.  I have the code that runs through a structure of event whenever the value of the control changes.  I can see that this code executes in fact when I click on the control via the front panel.  HOWEVER - when something is generated in the FPGA finally changes the value of the control, the structure of the event does not, even if I see the value of the change of control on my front.

  A specific example, I have a control named CLIENT_LB.  When I click on CLIENT_LB, I see it lights up, and I see the event structure code run.  Now, if I have the FPGA process to set CLIENT_LB to 0, I see unlight on my front, but does not run the code structure of the event.  I have probes in place who have checked the associated local variable CLIENT_LB evolving impact of values.  The structure of the event reads: 'CLIENT_LB': value change.

  Shouldn't an event structure "value change" run when the value changes, regardless of whether if it happened manually (i.e. me by clicking on the control) or automatically (i.e. the FPGA written in VI and changes the value of the control)?

  The VI is great, and you would not be able to test it in any case unrelated to the material, to remedy that I've attached 2 screenshots, I have described below.

  1. This is where the string from the FPGA analysis occurs.  The chain between the sub - VI, and then the data chain part is hidden to determine if the Boolean value of the control is true or false.  I put a probe on CLIENT_LB, and I see that as the FPGA changes the value of the register, CLIENT_LB passes from false to true as a result.  I checked this several times.

  2. it is the structure of the event.  This code runs when I click on CLIENT_LB on my face, but does not run when the peak CLIENT_LB #1 local variable is changed.

  Writing to variables never fires events to "change the value. If writing should raise this event, use the property "Value (follow the signs).

  Norbert

• Reading of RS232 event structure

  Hello

  I use the Write.vi to read RS232 attached as a starting point and do RS232 - help.vi him. successfully, the original written 1 posts, then wait a little, then reads 1 message. What I'm trying to do is to be able to read several messages. So I would write 1 message and I would read 1, 2 or 3 messages back or however many messages to ever come back, I guess that.

  Here is how I modified the original vi to get where I am now:

  I tried to add a structure of the event around half 'read' RS232 program. My structure of event triggers when the bytes to read the changes, this value can range from 0 to several bytes to be read, or muliple bytes to read 0. Up to half of the time I would trigger and not need, so I then added the accession of case which only works when the bytes to read the value is not 0, which means that it must be something waiting to be read whenever the program inserts this box. (I hope that's clear).

  At the moment, my program will not read and I don't know why. Through the program of first base, I can read and write properly. (I just hooked pins 2 and 3 on my cable so I read everything I write for testing purposes). So I know that the problem is spoil me the 2nd joint program

  Any help would be appreciated! Thank you.

  EDIT: I added 2 .jpgs incase you are on an different labview version.

  Better.

  But I don't think that permutation of the structure of the event for the structure of the case actually has really helped what.  In fact he madet worse.  You had the case of locking Panel event before the value until the end of the event.  But with the structure of the event within the structure of the case, there is a chance that the structure of the event will never run and therefore the façade will be locked up forever.

  1. you want to only 1 VISA close.

  2. event structure has been set.  I also added an event for writing switch is restored.  So now, it'll write if you change the channel or when you turn the switch to True.  (Note, you will not be able to always send the same string as in the original example because you must press the power button or change the channel.

  3. I used the structure of the event to stop the loop of both Scripture by trigger on the event that the button is pressed.

  4. I don't know what you mean by a «black» read

• leads the value change in the structure of the event

  Hello

  Please the the VI attached.

  I would like to know what event triggers when the value true or false of the changes led?

  In the case of structure above the structure of the event, the values of true or false of the led are changed.

  From the change, the analog output for Acquisition Card changes. However, the change event of the value in the structure of the event never fires, I know that I run the Vi with the selected highlight enforcement tool.

  Thank you

  Venkat Rao

  Changing the value in an event structure occurs only if one of the two following situations occurs.

  1. the user who modifies the control on front panel.  That may not happen since these LEDs are indicators and does not control.

  2. the program writes a value of property of the Value indicator/control (signalling) node.  Writing to the terminal of the indicator, or the local control variable / indicator not fire the event.  Given that you do not use value property (signalling) nodes in your program from this moment, won't happen either.

  Note that the value change event is a bit misnamed.  The change event is triggered, even if you do not actually change the data.  So if your LED is currently worth, and you write a True Boolean value for the Value property node (signalling), the event always fires even if you're not technically change the data.

• Record event blocks LabVIEW if the event Type is not selected.

  Hi I think that found a possible bug in LV2011 SP1.

  -Thread a property node of event Reg on the dynamic event record Terminal of a structure of event

  -Add a case to the event

  -Click on the dynamic event

  -LV accidents

  The source code included, try adding the unspecified event and look like LV breaks down.

  BR,

  / Roger

  Hi Roger,

  I doubt it. If you first select the event in the node property and then add the event to the event, you do not get an accident (I don't have at least let me know if you do). However, if boring and annoying is when it happens, there is a simple solution to the problem, which probably means that it will not be fixed on the previous version.

  Johan BR

• Structure of the event in the event structure

  Is it possible that I can have a structure of the event, which is in another structure of the event? When I run the code, I can't use other buttons. (See chart for details)

  

  Do not put the event structures in the structures of the event! There is never any reason to do so.

  Redefine architecture your code in a correct state machine.

  (By default, events lock the façade until the event ends and if you raise the event internal or external, first of all, the other event can never fire because the current event can never accomplish or is inaccessible by data stream.)

• help of event structure

  Hello

  Attached is a simplified version of my program, but that is the problem. I have labview update of a string, so in the program copied string1 to string2. When channel 2 is changed, I want that the structure of the event to turn on a light for 1 second.

  It works if I manually update string2, not when labview copies a value in string2. For example, change string1 and string2 update labview does not raise the changed event string2, but if I type manually directly in string2, light works as it should.

  Any ideas on how to change the properties or events so that the structure of the event resumes the value change when labview updates the string 2 and not only I type directly in string2?

  Thank you.

  Hello gemini,.

  When you trigger an event in each iteration of the loop, you will always have the light...

  -Create a valuechange event 'string' which triggers the string2...

  -You need not wait multi-object when you use the time-out of the structure of the event...

  -You must create an event of STOP button too...