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Can "Play Sound Files" plays two files simultaneously?

November 6, 2016, 10:07 am
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Hi all,

 

I'm working on a piano project. I built the following vi for testing. When the falling edge is detected, two "Play Sound Files" play two different .wav files at the same time. 

 

It turns out when the case structure is activated, two sound files are not synchronized, there's a tiny delay between two playing. However, if a falling edge is detected again before the playing ends, two sound files will be totally synchronized.

 

Could anyone tell me what's going on there? Two "Play Sound Files" are placed in the same case structure, but why there's a delay between two playing. 

 

Any help will be appreciated.

 

test.jpg

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Delete some clusters from an array

November 6, 2016, 12:52 pm
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Hi,

I have an array of clusters which are composed by two real numbers, during my algorithm sometime happens that that the two numbers are marked as NaN, I want to remove those clusters from the array, how can I do?

 

Thank you 

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FET measurement

November 6, 2016, 3:58 pm
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Hi there,

We have a Keysight (Agilent) B2902a measurement unit and wanna get FET or transistor characterization. We tried something but there is a problem in channel 1 and 2 synchronization i think. I've seen a topic about it but didn't actually comprehend. Are there any working .vi for b29xx series about it? or do you tell me what can i do?

sweep with 2 channels works for me too. at least i can learn logic.

 

Thanks for your help already. 

 

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How to hidden Labview startup window when Teststand Start Loading

November 6, 2016, 7:06 pm
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I have Teststand development enviroment and Labview development enviroment installed on my computer,my teststand application use Labview adapter. Question is each time when I start running Teststand application,Labview start-up window will auto pop-up, I want to customize this behavior to let Labview just show in the taskbar.

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Unable to save data to text file

November 6, 2016, 9:06 pm
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Hello, I would like to ask if you could tell me if anything is wrong with my block diagram.. 

 

I am trying to save BPM values streaming in (the orange line) in this diagram. I would like to have BPM values to be recorded in my txt file after I have stopped the run. Right now, I have my headers, personal particulars keyed in, and a 0 displayed on my txt. I got a 0 as my only BPM value after the run. I'm not sure how to get all my data values to be displayed in the text file. Would gladly appreciate if you could give me some pointers! I have attached the image in this message. (: Thanks!

 

 

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Strange problem with remote front panel - PXI RT

November 7, 2016, 8:53 am
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 Hello!

 

I am facing a very strange behaviour with my PXI recently, and I ask for help and suggestions what might cause this.

PC side: win7, x64, LV 2015 32bit,

PXI: RT (pharlap)

 

PXI is connected via local Ethernet to PC. Some time ago I have developed a RT application to run on this PXI unit. For diagnostic reasons, for monitoring and even for manual control, I published the FP of the main vi of this application. I have followed this procedure: http://digital.ni.com/public.nsf/allkb/AB6C6841486E84EA862576C8005A0C26

Everything worked as I wanted, I could see using my web browser live data coming from some gpib devices connected to the PXI, and I had the feature even to initiate some gpib commands when it was needed for diagnostic reasons. 

 

A few days ago, I had to move the project to another folder in the local hard drive on the PC. I have got some problem when I tried to build the project again after changing some parts of the source code. One problem was that the build could not locate the html file, even if it was still under the www folder inside the Labview2015 install on the PC. So what I did, I just create a new html file using the same main vi like before, and it was working again.

After this fix, I realised that now I can access the same vi via two html files: PXI-master.html (the old one), and the new Master.html. I tried to "kill/wipe" the old html file, I have deleted it from the PC (www folder), and also from the RT target using the web file interface (it was sitting on the RT at two locations). I re-deployed the new built from the PC to the target, and rebooted the target. Surprise! I could still access the vi front panel using the old html address! And it was not the cache of the browser, I could see the live measurement data changing! what the heck! Smiley Happy))

 

Anyway, I could have lived with this situation, who cares, I can access the front panel via two addresses, not only one. However, a real serious problem appeared! Namely, whatever code modification I make on the main vi, like adding a new indicator, it appears in the web published websites, but does not change value!!! Whatever was the default value of this indicator, its status stays like that forever, even if i am sure it is changing inside the code when it is running! Therefore, i cannot continue the development of my project any more, I cannot examine changes in my application via web browser. Mysteriously, the published web browsers still showing love measurement data accurately.

 

I am asking for help, and info to understand deeper how this web publishing works on RT. Some questions:

1. How is that possible that the old html still functions? I have deleted it from everywhere. OK, I did not restarted the PC, but I can try this tomorrow.

2. How can I kill and wipe clean my PXI from this html and my RT app? I do not want a hard reset, I would rather avoid re installing every software on this PXI...

3. Where does this html live/exists? How could the PXI revive it?

4. How is that possible that a new indicator appears on the FP in the web browser, but does not function at all??? All old indicators are OK!

 

Thanks very much for the help! Smiley Happy

 

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How to send "Hello World" from one USRP2932 to another. (LabVIEW interface)

November 7, 2016, 8:53 am
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Hello

 

I wanted to have an idea about how to send 1 data (consider it be hello world) from 1 USRP to another using LabVIEW. 

Help is greatly appreciated.

Thanks 

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Another CRC16 Question...

November 7, 2016, 8:56 am
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Hello.  Been digging through many of the CRC16 discussions on NI Forums and various other C forums as well as wikipedia.  One question that doesn't seem to be addressed: what is the initial value?  My client asked for CRC16 with following polynomial: X16 + X15 + X5 + X2 + 1 but did not specify an Initial value.  This being my first go at this, I have to ask myself (and am now asking you) is there an initial value standard?  Is the initial value hidden in the polynomial?  Does X16 mean initial value = 0xFFFF?  I'd prefer to ask LabVIEW forums first cuz you won't judge me before I ask client for an initial value.  I know y'all love CRC16 questions.  Any help here would be hot.

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Changing graph size

November 7, 2016, 9:23 am
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Hello,

 

I am trying to create a pop up window that offers default graph sizes based on the monitor resolution and also a custom option where the user can define their own graph size. However, I am struggling to get the property nodes (to the graph size) to work in my case structure in my sub VI. I have tried using control references in my sub VI to control the size of the graph - which is located on the main VI - but I can't get it to work.

 

Any help is appreciated!

 

Thank you

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Thorlabs KDC101 Communication

November 7, 2016, 9:49 am
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Hello,

 

I recently received a Thorlabs KDC101 controller and have been instructed to build a custom GUI for it (not using ActiveX and APT). So my question is, has anyone done this before? There are not any LV drivers for this particular controller that I am aware of. I have been trying to set up initial communication via USB and serial, but have not been successful. I am planning on sending commands to the controller via strings, but I am also not sure on the syntax to send the strings. The attached PDF has me confused, maybe someone could help me with that and/or the communication part?

 

Thanks in advance for any help!

SM

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labview convert 5.0 to 2009. Analog input

November 7, 2016, 10:14 am
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I can convert from 5.0 to LabView 6 or 8.  I cannot convert the part from 5.0 Analog Input.  What is the new form?  Is there sample code?

 

Tahnk you

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Windows COM port number not aligned to VISA Resource String

November 7, 2016, 11:32 am
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Historically, if you knew the Windows com port number of a serial device you could predict the VISA resource string needed to communicate to it. For example, if my device was attached to COM8 in Windows, I could contstruct the following VISA resource string ASRL8::INSTR to use with the VISA functions to access it.

 

Recently, I was part of a debugging effort in our application to determine why the COM device would be detected but could not be opened by VISA. I should note that the detection method is not based on VISA. We use a Windows command line program to list all COM port numbers and filter out all COM port which do not have a specific description. Turns out that while the device shows up as COM8 in Windows Device Manager, the actual VISA resource string to use for it was ASRL9::INSTR.

 

I've never seen a case where the COM port number did not have a direct associated to the VISA resource string used to access it. We have a workaround in place now where the user reassigns the COM port number in Windows to some higher number that has never been used before. But I was wondering if anyone had any insight on how this could happen?

 

We are using NI VISA 14.0 runtime. The user's OS is Windows 10 x64. Before we discovered the workaround, we were able to reproduce the issue in both 32-bit and 64-bit versions of our software which is build in LabVIEW 2014. We have tried to reporduce the issue here without any luck. I have also attached the user's visconf.ini which shows that for some reason COM8 is mapped to ASRL9::INSTR.

 

Is ASRL8::INSTR reserved for something special?

 

Thanks.

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FPGA Project Error Message: Write Method in an Unsupported Clock Domain

November 7, 2016, 11:32 am
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I am new to LabVIEW FPGA, and having a lot of trouble with it. Ignoring "ultimate goals" for now, I am currently focusing on just getting some kind of signal to output from my NI PXIe-7972 FPGA + NI PXIe-5783 adapter module. Any signal. If it outputted a wave in the shape of a middle finger on my oscilloscope, I'd be overjoyed because at least it would be something.

 

I have attached a screenshot showing all of my windows (project, block diagram, interface, and error window). I used a built-in example from the path /program files/National Instruments/LabVIEW 2015/examples/R Series/Basic IO/Analog Output. I created a new FPGA target for the PXIe-7672, added the 200 MHz clock needed to eliminate the red exclamation mark next to the IO Module in the Project, and transferred the example VI to the new target. (I have also tried this by making a completely new project and copying a clean copy of the VI into it). In the block diagram, I changed the example connectors to be (what I believe are) the outputs on my PXIe-5783 adapter module.

 

Everything seems fine from my limited-knowledge view. But when I try to compile / run the VI for the first time, I get the same error, seen in the top left corner of the screenshot, of the form "The <method> <IOType> for <IOResource> is used in a clock domain that does not support it. The supported clock domain is <RequiredClockDomain>".

 

I can't for the life of me figure out what this means or how to fix it. The project goals that I'm trying to accomplish are a LOT more complicated than this, so it's getting to be really disheartening. Can someone please help me with this?

Thank you.

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Control Stepper motor using USB port

November 7, 2016, 11:43 am
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Hello,

I'm new to using LabView. I have started working on a project that involves designing a VI to control a stepper motor. The current setup has a motor and an interface  device [most probably similar to DAQ] which converts commands from their software through USB Comm port and interfaces to the motor. The company that manufactured the machine is no longer providing tech support as they have stopped the product line. The only resource I have is a manual to use the software. 

 

I have used LabView DAQ setup to control motor before but, in this case, I have no idea how to read and control the device through the USB. 

Brief description of the software:

The setup installs drivers to configure a comm port and the software has commands for the number of rotations,  speed, acceleration, the number of cycles [loops], delay and a reset to initial position. 

I would appreciate any suggestions on how to start or tackle the problem and build the VI to control the existing setup. 

 

Thank you.

PS. I don't know what is inside the box and I'm a beginner. 

 

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USB 6008 with Raspberry Pi

November 7, 2016, 12:02 pm
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Simple question, Can you use standard NI USB DAQ devices such as 6008/6009 with the 2014 Home LV ver.  with VI deployed to a Raspberry Pi as simply as you can if the VI was running on a regular windows PC?

 

Thanks,

 

Alan

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Imminent Community website Disruption warning

November 7, 2016, 12:46 pm
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I invite you all to take a look at this NI blog post about the incoming changes to the Users Community's side of the NI website. If you are not a user, no worries. If you have accumulated bookmarks and subscriptions like me, expect to loose the former and have to reset the latter.

Not sure how many of you are aware of the details, but I discovered that post over the weekend while waiting for coffee to start having an effect on my brain cells, and this was quite a shocker.

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How to autoscale multiple Y Axes in waveform chart & waveform graph

November 7, 2016, 12:20 pm
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 Hello Everyone, i have been struggling with this one issue. I want to plot multiple Y-axes on a waveform chart. I get the 1st chart auto-scaled as per data, but the rest of the 'Duplicate Scales' fail to autoscale themselves based on the data.

How can I get this resolved?

 

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how to use sbRIO-9607 on-board USB port in RealTime VI

November 7, 2016, 12:21 pm
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Hi,

 

I am new to RIO programming and  would like to use the on-board USB port on a sbRIO-9607 to acquire data in a Real Time VI. Do I have to use VISA in Realtime? or do I have to use FPGA programming

 

Regards

Goku

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NIUninstaller does not exist under Shared, nor Add/Remove does not display National Instruments Software

November 7, 2016, 1:15 pm
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I need to uninstall labview but the NIUninstaller does not exist.  I have labview files on the c:\ drive and duplicated on my d:\ drive.  Cannot remove them via the add/remove apps selection in control settings.  Labview 2016, Windows 10

I cannot open up certain VI's as it indicates that the the simulation module is missing - tried downloading but still not working - hence wanting to start from a clean slate.

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IMAQ Write File 2 creates "motion blur" artifacts in the saved tiff images

November 7, 2016, 3:02 pm
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I have a microscope system that can image a large sample by moving and imaging it in x and y directions and then create a mosaic image. The process is like this: take one image --> move one step --> check if moving is completed --> take another image --> move one step -->......

 

I am using IMAQ Create --> IMAQ Array to Image --> IMAQ Write File 2 --> IMAQ Dispose to save the images in a tiff format (attached a screenshot of the code). 

 

The problem is, if I save the images, they will give me some artifacts that look like a " motion blur", as if the sample is not moving as a unit from top to bottom which is not possible, and are random in time and space (attached one example of the normal and the "motion blur" images cropped from the same position of two images took with different delay time). However, if I am using live mode (without saving the images), the images are quite smooth. I tried to add delay when saving images; it helped when I increased the delay time to 1 second, but that was too slow and wouldn't solve it throughly. The artifacts still happened. 

 

I am pretty sure the xy movement has been finished before each image acquisition, but I am not sure how to check if the acquistion has been finished before the movement. Could it be the speed of writing file that causes this issue? If so, is there any way to solve it without sacrificing the speed?

 

Other information that may needed:

    Software: Labview 2014 Windows 64bit

    Acquistion card: NI PCI 6255

    Camera: Hamamatsu ORCA Flash 4.0

    Image size: 2048*2048, 16bit (about 8MB per image)

 

 

Thanks!

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