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Unsure how to pull a continuous scalar value from waveform of signal to compare using Schmitt Trigger

November 19, 2018, 9:08 pm
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Hello! I have attached images of my labview VI as well as the actual program for reference.

 

Preface: I am using the DAQmx software to acquire a voltage, but I only have the software installed on the desktop in my lab, not my laptop which is why you are seeing the ? blocks. Don't worry, I am able to acquire the voltage correctly!

 

The desired result: I am wanting to acquire the voltage waveform and pull out a value at the current time to be compared to the logic operations shown in the bottom portion of the block diagram (the Schmitt Trigger). When the original waveform passes the upper and lower limits, the schmitt trigger boolean turns on and off respectively. Ultimately, I hope to use the schmitt trigger logic operation to then build a square waveform corresponding to the time when the schmitt trigger boolean turns on and off. 

 

The issue: I originally tried comparing the waveform directly to the logic operations and of course was unsuccessful. I then tried following some forum posts to try to convert the waveform into an array, and then to index the array to a given element so that it would output the value at the current array length. I think my issue is that my sampling rate is so large (100000 samples/sec) that I need to have an array that is constantly increasing in length. Either that, or I need some other way to pull a continuous value from the waveform so that I can then use the schmitt trigger to build a square waveform.

 

Am I going in the right direction with this? Or is there an easier way to compare a waveform to the logic shown in the bottom of the block diagram? I am so thankful for any help you could offer me.

 

Thank you,

 

Cason Smith

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Windows media player is not working when put in tab Control

November 19, 2018, 11:43 pm
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I had some other programs in my tab control and when i tried to put windows media player also in tab control it does not work. If there is no other programs in my tab control then the windows media player works. why is this so? i really need a solution to this because i want to have windows media player working with other programs in my tab control when i click run. You can also make changes in my vi file since i upload it here 

 

Untitled11.pngUntitled.png

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FPGA IP Integration Node: Error in generating support files

November 20, 2018, 12:52 am
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I am trying to integrate a VHDL code which uses two Xilinx IPs DDS compiler and Adder/Subtracter. 

 

In the FPGA IP Integration Node Properties dialogue box, the top level .vhd file and the IP core component .vhd files were loaded.  Here is the error when I click on 'Generate' in page three. - 

 

Generating simulation model for this IP...
Vivado Simulator 2017.2
Copyright 1986-1999, 2001-2016 Xilinx, Inc. All Rights Reserved.
.

.
ERROR: [VRFC 10-149] 'dds_compiler_v6_0_16' is not compiled in library dds_compiler_v6_0_16 [C:\NIFPGA\iptemp\ipinF0828607E83C4C0CAF350A24308980DB\Vivado\sin_cos1.vhd:57]
INFO: [VRFC 10-307] analyzing entity sin_cos1
ERROR: [VRFC 10-1504] unit sin_cos1 ignored due to previous errors [C:\NIFPGA\iptemp\ipinF0828607E83C4C0CAF350A24308980DB\Vivado\sin_cos1.vhd:59]
INFO: [VRFC 10-240] VHDL file C:/NIFPGA/iptemp/ipinF0828607E83C4C0CAF350A24308980DB/Vivado/sin_cos1.vhd ignored due to errors
Generated IP unsuccessfully. Your source file(s) can't work for the FPGA famili(es) you select. Fix the above error(s) or warning(s) and generate the IP again, or go back to previous page to reselect FPGA Family Support.

 

Am I missing adding necessary files in page 1?  Tried after selecting different FPGA families. 

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Switching a relay on/off using DAQ asiistant

November 20, 2018, 1:37 am
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Hello, I am trying to create a VI that switches my relay on for a specific amount of time and then off for sometime, on repeat. switching it on works but i don't know how to switch it off and repeat. i have attached my VI, please do tell me what alteration is necessary to make it work. 

Thankyou

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Num control starts over with the mouse wheel

November 20, 2018, 1:52 am
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Hi everyone,

 

I have an issue with my numeric controls when changing the value with the wheel of the mouse. When I increment to the maximum limit (lets say 10) and continue to roll the wheel, the control starts over to 0. Same when decreasing to 0, the next value is 10,then 9,8,7...

 

This only happens with the executable, not when I run the program in LabVIEW 18 32bits. The executable was tested on 2 computers, one only have the runtime installed. 

Changing the value with the arrows of the keyboard works fine, it does not go over the limits.

 

Yesterday I reproduced the problem with only a num control in a while loop. The control had the following properties (it also works with "coerce up/down") :

 Capture.PNG

 

The computer I work was ON for a few days. But last night, the power turned off and the computers shut down. This morning I turned on my computer, I built again the program to reproduce the problem, but the behaviour is now normal for the new executable. For the executable I created yesterday, the issue is still there.

 

Maybe the problem came from the builder ? With that in mind, I ran a previous build from a few weeks ago, everything is normal.

 

Does someone have an explanation ? How to avoid that to happen again ?

 

Yddet

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Find my serial number

November 20, 2018, 2:05 am
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Respected Sir,
I am a design engineer at Baseline Technology .We request you to help us
regarding the Application builder deactivation problem  in my PC .We recently
noticed that the application builder is deactivated. Unfortunately we lost the
serial no related to the product as they were purchased in 2006 and kept
unchecked for a long time.We contacted the NI branch at Bangalore and they
asked for the Purchase order no in order to find the original serial no through
NI records. As the records we were supposed to provide you were also missing we
kindly request you to look for the  serial number by our name "Baseline
Technology" from your records. I am expecting your cooperation.

Software Details: LabVIEW Application Builder  version 8.2.1
NI Hardware:  M63X33995 (Free form entry) device
Driver Version :  
Operating System:  Windows XP

Computr Id Smiley Very HappyTQ8-PFLD-HJ5G-DV7Z

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Co-simulate multiple mutisim modules in a labview application

November 20, 2018, 2:29 am
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Hi, 

I am trying to develop an application that co-simulates multiple Multisim circuits in a LabVIEW application.

As of now I am successful in running only 4 circuits at a given instance, but I need to run around 300 circuits in a single application, all the circuits has to run continuously as each one is dependent on the other. 

On trying to run 5 or more circuits, the system fails to assign resource(cpu) to the background Multisim processes.

May I know a better approach to solve this issue?

Thank You.

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Intensity graph

November 20, 2018, 2:50 am
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Hello everyone,

 

I'm working on my senior design project, I'm designing microwave imaging system where I'm scanning a defected sample using sensor and getting the voltage at each scanning point as analog input. the scanner have two encoders, for both X-Y axis and the values of the axis are displayed in array separately to show the sensor position. 

 

I need to display all of these data in intensity graph, so X & Y axis will represent the position of the sensor and the intensity should represent the voltage values. I didn't know how create the intensity graph, I have attached the code as well.

 

 

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Disabled Node Coercion Issue

November 20, 2018, 3:50 am
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Hi all,

 

A really pedantic issue as the code works fine, however its been annoying me for a while now. Smiley LOL 

 

When trying to "Disable and grey out" a numeric indicator using the "Disabled" property node, I seem to be getting a coercion dot and I'm not quite sure why. 
Using the contextual help as a guide, it explains the node takes an "Unsigned 8-bit byte integer". Which is what I've converted my input to, however it seems LabView is still unhappy and changes the data representation to something else, hence the coercion dot appearing. 

 

Very puzzled at the moment, I've been trying to work this out on my own for an embarrassingly long amount of time, so any help would be really appreciated, thanks!

 

I've included a very simple image showing what I mean.

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Gaussian Peak Fit vi - valley fitting

November 20, 2018, 4:38 am
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Hi Everyone

I have been looking for this info everywhere and could not find it.

Is it possible to use the function Gaussian Peak Fit to fit a valley?

How to set parameter bounds for that case?

Looking forward to your suggestions.

Best regards,

   Joao

PS: I am using Labview 2012. If you send any example, could you please take that into account?

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Design and test External power supply to wireless temperature sensor

November 20, 2018, 4:40 am
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I need to design a DC power supply, I am connecting 3.99v battery to connect it in input but exact external power requires around 3.3v only instead of using regulator how can I send the exact amount of power supply to wireless temperature sensor if 2AA battery is not working in it, before working it directly can I test it with LAB view.

Any kind circuit suggestion to give exact 3.3 v power supply with the help zener diode or simple diode will be a great help.

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Continous contour move with SoftMotion

November 20, 2018, 5:12 am
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Hi everybody,

 

I'm trying to program a control system for a cartesian positioning system with three axes. Therefore I programed a test VI where I'm trying to perform a continous contour move with my coordinated axes. One loop is writing points from an array into a cluster and is sending that cluster with a real time fifo to another loop where I use the Straight-line-move "polyline" to generate a move profile out of these points. Then I want to update my table ressource in order to let the contour move drive off the generated move profile. I can run the VI (once) without any problems. But as soon as I try to re-run it there is no table space available although I overwrite the table buffer in an initializing process.

 

Does anybody know what's wrong here or how I could solve this problem?

 

Many thanks in advance

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Programmatically Creating a Simulated Axis in Softmotion

November 20, 2018, 5:31 am
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Hi!

Is it possible to create simulated axis in a way other than adding it to the project? Either programmatically or in NI MAX, like it is possible to create a simulated DAQ. 

 

Cheers

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CAN comms not working

November 20, 2018, 6:28 am
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Hello to everyone,

 

I'm working with a sbRIO9607, trying to establish a CAN communication. To do this I'm using the on board CAN connector and the example programme "NI Embedded CAN for RIO". The programme remains in the block "CANRead.vi" and I obtain this error:

 

"

Warning 35024 occurred at an unidentified location
Possible reason(s):
The requested operation did not complete in time.

"

I'm trying to read from a CAN slave (it is working for the CAN master, the sbRIO, to read), but I can't assure where is the problem: in the CAN slave that isn't working or the programme that I'm using is not well configured.

 

Thank you in advance. 

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Managing LabVIEW Project Assets

November 20, 2018, 6:58 am
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Hello,

I have a fairly large LabVIEW project which I have organized into various folders and sub-folders on disk as seen in the following screenshot.image.png

 

 

I am following the design guide for building an effective hardware abstraction layer so I have parent interface classes in the HAL folder (grouped by the type of hardware) and the actual implementations in the DSSP folder (again grouped by the type).  On of the member VI methods I want to have for every piece of hardware is one which returns an image for the hardware called Get Image.vi.  This will be overridden from the GenericHALObject by the actual hardware objects and dynamic dispatching will call the correct VI.

 

My question is how to organize these images in the source code and final built application.  Right now I am storing the images for each DSSP in the folder with the LabVIEW class and am having the Get Image method use the path of the current VI to find the image.  However, I know this will not work when calling the GenericHALObject method nor when I build the final application into an executable.  Ideally the images (and any other files I need) would either be embedded in the final executable or better yet with a DLL or something similar) that contains the DSSP or alternatively the actual file gets placed with the EXE.  I also need this to be able to work when debugging the application within the development environment.

 

Any suggestions as to the best way to do this?

Thanks!

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USB 3.1/ USRP

November 20, 2018, 7:58 am
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I am attempting to use a USB 3.1 board (Rosewill RC-509) to obtain higher transfer speed to and from a USRP-2901.

 

I can see the USRP-2901 in device manager when it is connected to the 3.1 port. However Labview cannot communicate with the USRP.

 

The USRP-2901 works fine when connected to any other USB ports using the same cable. The USB 3.1 port works with a thumb drive.

 

Any ideas? Is Labview not able to deal with a USB 3.1 port??

 

(Labview 2017/ USRP drivers 18.0/ Windows 7 Pro)

 

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PSD magnitudes

November 20, 2018, 8:29 am
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Hi,

We are trying to study the PSD of a sine signal. We are finding that the magnitude  of the output of the PSD VI does not correspond to the value given by the math equation "A²/4" at the frequency of the sine (and A being the amplitude of the sine).

Moreover the magnitude of the output seems dependent on the number of points generated by the sine wave VI.

 

Can someone help us understand where this problem is coming from?

 

Thanks

Ella

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[LABVIEW] Utiliser un GPIB-USB Keysight avec LabVIEW 2012

November 20, 2018, 9:18 am
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Separate VI Operating on Same Object

November 20, 2018, 9:34 am
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Hello,

 

I am trying to accomplish something in LabVIEW which is usually trivial in a language which has the natural notion of references and pointers.  In my example scenario I have two VIs, A and B, which will be running in parallel (a main window and a popup window).  I have a class which represents a physical piece of hardware, for example a motor.  VI A has a few controls for making the motor move.  VI B has a few indicators which display the current status and position of the motor.

 

Normally it would be simple enough for each VI to have pointers to the same physical motor object and use some mechanism to notify the VIs of updates to the object (for example, the C++ framework Qt has an event mechanism).  However, since data is passed by value and copies in LabVIEW and objects really don't have "state" as far as I can tell, this seems to be a challenge to accomplish.

 

I have tried the idea of creating custom user events to notify each VI of changes.  The problem with this method (or at least my implementation of it) is that I have to create a new custom event for anything new I potentially add to the object (and this is not truly part of the class so I lose encapsulation and modularity).

 

Are there any good methods for doing something like this in LabVIEW?  I would potentially want the ability to add any number of parallel VIs that all can act upon and receive updates from the same object.

 

Thank you!

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Coerce to Type: Ctl Disabled enum to Page Enabled enum

November 20, 2018, 10:31 am
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Ugh!

When converting an enum for a control's Disabled property to an enum for a tab page's Page Enabled State, you have to send it around the mulberry bush (WHY?).

en.png

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