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Cleaning up VI's.

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Hi, I'm relatively new and am learning through the school of hard knocks.... My background is using tools like Cadence for schematic capture and IC layout. There are a few things you can do in Cadence that I just can't seem to figure out how to do with Labview which I believe would make my VI's much cleaner and easier to follow once I figure out how to do them.

 

These are:

 

1. How do you resize and icon? I created an icon with 12 terminals. What a fugly mess once it's wired up. It would be nice if I could enlarge this and manually move the terminals to group them appropriately.

 

2. This is a corollary to my first question. How do you make virtual connection? IOW, if two signals are called the same thing they should be virtually connected. Therefore, there is no need to run a wire between them. In my current example, 11 of 12 inputs to the VI are top level controls the user of the VI will be selecting.

 

3. Or, what about making a bus? Then I could tie together similar wire types. In my current example, four of the twelve wires are GPIB addresses; data type wires. I could tie these together as a bus (e.g. GPIB(1-4)),  and make one terminal on the icon, and run them to where the user controls are and separate them back to their individual components there.

 

 

Thanks!

 

 


Tricky cRIO web services deployment

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Is there a way to build and deploy web services programmatically as a plug-in to a remote sbRIO?  

 

We have a working plug-in mechanism that uses source distributions for the plug-ins.  It's not clear to me if web services can be included in a source distritubtion build spec.  And then there's the whole question of what magic Labview does when deploying a web service.  We use TCP for communication, so in theory I think we should be able to deploy web services programmatically on the target itself--yet I haven't found any documentation explaining exactly what changes Labview makes to the target when a web service is deployed.
 
Anyone have insight into the best way to achieve this requirement?

Cluster of boolean controls does not update in the expected way

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Hello,

I am confused about the following issue: In the attached Test Cluster of Boolean Controls Functionality.vi, I have a cluster of bolean controls, some disabled and grayed out, some enabled. If I click on one of the two enabled boolean controls, and then on the other, I want the boolean control selected first to reset to False. The indicator Update Cluster shows the desired behavior. What confuses me, is that the New Value does not update accordingly. Once I have clicked on both booleans at least once, the New Value stays [TRUE,TRUE] at all times, and the event structure no longer executes.

 

I already have a workaround, as shown in the Test Cluster of Boolean Controls Functionality Workaround.vi, but this does not look "nice", as it is more complicated than necessary. Does anybody know why the New Value does not update as expected? Please advise. Thank you.

Best regards,

Peter

How do I use ni 9205 with cRio for a simple voltage measurement?

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Hello everyone!

 

I have some experience with LabView but none with this hardware. I don't have FPGA installed for LabView, but I don't think I need it for cRio, unless I'm mistaken. I just have a cRio connected to my laptop via ethernet with the 9205 module installed. I have the latest RIO drivers installed, along with the latest version of LabView. I just want to take a simple voltage measurement (I have a positive lead and negative lead of a battery connected to ports 0 and 1 respectively on the 9205) with LabView, but I have no idea how to go about this. Any help would be greatly appreciated, I have thoroughly perused the manuals and tutorials and they all seem to be for using FPGA which I really don't want to buy. I tried using Scan Interface Mode but LabView wouldn't let me make a project in that mode (it said I was missing a bunch of controls/subVIs...) I've been stuck on this for a week so any help would be very VERY appreciated! Thanks so much!

DIAdem load data

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Tried to load an LABVIEW example to automate the DIAdem tasks,  I got error the VI could not find the "DIAdem Load Data.vi".  

 

Where can I find this VI?  

 

Thank you

Multiple concurrent LabVIEW apps sharing card resources in one cDAQ chassis

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I'm looking for help, reallly a yes/no answer and/or pointers/suggestions as to the feasability of as well as how to have multiple LabVIEW apps run concurrently and share resources (cards) from a single cDAQ module.  The background is that I have an array identical of LabVIEW test systems that are used to perform testing in environmental chambers, and there are many different standardized tests that they run, ideally some (that use different resources) at the same time.  The problem is that different tests use different subsets of the cDAQ resouces, but the goal is to be able to run multiple tests/apps (for example, for multiple pieces of equipment in the environmental chamber) at the same time).  Can LabVIEW apps be structured such that they can share a module in a cDAQ chassis?  For example, if I have 20 thermocouples connected to the chassis that can all be scanned/read at the same rate (around once/second), can one app read some of them and another app read others of them virtually concurrently, perhaps by sharing a common task?

 

Any advice as to how something like this could/should be done would be appreciated.

 

Thanks.

Talon SRX Labview Programming - Voltage Ramp

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So according to this Talon SRX Software Reference Manual, on page 33, I assume I am supposed to wire the SET VOLTAGE RAMP to a MOTOR control thing. How would you ramp the voltage for the motors if you're using the ARCADE DRIVE palette?

Talon SRX Labview Programming - Voltage Ramp

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So according to this Talon SRX Software Reference Manual, on page 33, I assume I am supposed to wire the SET VOLTAGE RAMP to a MOTOR control thing. How would you ramp the voltage for the motors if you're using the ARCADE DRIVE palette?


LabVIEW2014f1 bug: unhandled CannotUnloadAppDomainException

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Need help from NI to fix this CannotUnloadAppDomain exception.

It leads to a crash of the LabView IDE or any other calling instance.

Attached is a small VisualStudio project to build a ThreadRunner.dll and a VI referencing the dll. The crash happens 10 or more seconds after the VI execution finished.

Attach to the LabVIEW process to catch the exception in the Visual Studio debugger.

 

This is new to LabVIEW 2014!!!  In LabVIEW 2013 the exception will be handled in the background.

 

 

LV2014f1Crash.jpg

 

 

UnloadAppDomainException.jpg

 

System.CannotUnloadAppDomainException was unhandled
  HResult=-2146234347
  Message=Fehler beim Entladen der Anwendungsdomäne. (Ausnahme von HRESULT: 0x80131015)
  Source=mscorlib
  StackTrace:
       bei System.AppDomain.Unload(AppDomain domain)
       bei UnloadAppDomainInThreadProc(Object domain)
       bei System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
       bei System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       bei System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
       bei System.Threading.ThreadPoolWorkQueue.Dispatch()
       bei System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

 

 

 

 

How identify type of control in LabVIEW 2013?

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Hi,

 

I wanna identify type of each control from front panel of a main VI. When a control is type "tabcontrol" I will determine all contained controls of each tab.

 

I changed to LabVIEW 2013 for a short time. Unfortunately in LabVIEW 2013 I didn't find a property to identify the type of a control. A condensed code with my problem you can find in attachment.

 

Can anybody tells me, how I can solve this in LabVIEW 2013? Thank you in advance.

 

Christian

license activation problem

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Hi all,

 

Does the serial number bought for a Korean verion of LabVIEW 2012 works with English version?

Error -200431 occurred at DAQmx Create Channel (AI-Acceleration-Accelerometer).vi

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Hi,

 

I tried to use DAQmx Create Channel for Accelerometer yet  it respond with error (below). When i use NI max to measure accelerometer (AI-Acceleration-Accelerometer) , there is no error and i can see that acceloremeter works .

 

NI PXI 1042 and i use NI -4462 card to measure vibration vith acceloremeter.
ai_config.png

 

Error -200431 occurred at DAQmx Create Virtual Channel 

 

Possible reason(s):

Selected physical channel does not support the measurement type required by the virtual channel you are creating.

Create a channel of a measurement type that is supported by the physical channel, or select a physical channel that supports the measurement type.

Property: AI.MeasType
Requested Value:
You Can Select: Voltage, Sound Pressure:Microphone, Accelerometer, Position:Eddy Current Proximity Probe, Force:IEPE Sensor, Velocity:IEPE Sensor

Task Name: _unnamedTask<104>

 

 

 

How can I determine the center of a gaussian window?

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Hi,

 

I need to analyse a signal composed by 4 channels. I want to apply a gaussian window (and maybe try other window types too) with "window center" at different locations in the signal. Let's say that the signal is composed by 1000 points. I would like to apply different gaussian windows with center at point 100, 200, 300, 400, 500, ... Is it possible to do that?

 

Thank you!

system identification for power converter

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Dear All,

            i am working on system identification  for the buck converter . for this i generated variable duty cycle with 20KHz switching frequency on analog output AO1 of usb 6221, now i want to introduce perturbation PRBS in steady state. now my problem is to add perturbation on analog output. please suggest me how to do this on analog output.

 

thanks

 

with regards

gurpreet singh

Producer / Consumer loop set dynamic data element type

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Hey all,

 

 

I'm doing a simple excercise on producer / consumer loops. In my producer loop I'm aqcuiring audio and in the consumer loop I'm projecting it on a chart

 

Everything is working as I had in mind, the only thing bothering me is the way that I had to set the element type to the 'Obtain Queue' block in the beginning.

I knew of no better way to get the data type that I was using than just taking another 'Acquire Sound' Express VI and hooking that up. But that can't possibly be the only way to get this done, right?

 

Note: I know that I might not need to use a producer / consumer design pattern to get this done but I need to get a hold of the technique for some school work so I just came up with this excercise to get a hang of it.

 

Thanks in advance,

Al.


Finite Measurements Project template

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Hello,
I am using the Finite Measurements Project template for acceleration
acquisition using an accelerometer. I made changes to the project and it is
working properly except for these three major points:
1)  Copy Graph- How do I put a ask user to define file path (A pop-up window)? It only
allows me to change the file path in the block diagram window.

1.png
2) Update UI -I would like to change to a free running VI and update the main
user interface during an acquisition real time. How do I do this? I tried
adding a data display loop. But it is not working properly.

2.jpg
3) Analyze- I would like to press the analyze button and be able to convert the
acceleration data to an FFT in the frequency domain. But it is not able to export the FFT data into the Main.VI

3.jpg

Thanks in advance for your help.

LabVIEW "Allow debugging" option efficiency in executable

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I tried searching for this but too many false positives involving debugging an exe, or the same old line about code running faster in IDE without it checked.

 

But does this option being on/off for individual VI's affect the efficiency/speed of a built application?

 

Sorry if I'm asking a dumb question, but I've never actually seen this specific question answered.

How can I run a CVI panel in labview ???

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Seems simple enough... I want to create a DLL to be called from my labview VI using the "call library function". The DLL will have a panel that the user can navigate around and push buttons to invoke callbacks.

 

Seems simple enough, but when I try this the buttons do not work. If I try to compile the DLL with the "real time only" runtime support, then it does not like the "LoadPanel, DiscardPanel, RunUserInterface", etc...  vital commands to run a panel.

 

So what gives? anyone know how to create a DLL with an operable panel to be called from within a labview VI?

 

I guess I should clarify, the callbacks are CVI callbacks.

 

Much thanks in advance...

combox minus symbol not working ..

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Combox minus symbol not working (not showing). 

i have added picture . 

Problem on Normalized Frequency to original analog frequency

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I'm having a problem regarding normalized frequency.

 

The Sine wave .vi, says that the input to the frequency  must be a normalized frequency. What I did is tha I divide my frequency to the number of samples.

However, when I attached Tone Measurements to output signal of the sine wave, I'm not having a frequency of what i set. 

 

In my example my input frequency is 60 Hz however what was detected by the tone measurement was the normalized frequency which is 0.06.

 

How do I modify this VI, in order that i will have a frequency in 60 hZ, 

 

probelem.png

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