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Best way to transfer data between loops in FPGA VIs

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Hi,

 

I'm using a FlexRio Board PXIe 7962, with an I/O module 5781.

I've set the Top level Clock to 80MHz (Base Clk 40M), and I'm implementing two loops in the FPGa VI: In the first one, I'm using a SCTL (20M) where I'm getting Digitized Data (1.5MHz) from the NI 5781, then multiplying it by a DDS Signal (1.8MHz), then I'm filtering (band-pass around 300kHz)) the product.

My question is: If what I've implemented is correct, what is the best way to transfer the first loop data running at 20MHz, to the second one running at 1MHz ? (without loosing Data of course since the signal interest is at 300kHz)

and similarly : what is the best way to transfer the second loop data running at 1MHz, to a Host VI ? DMA FIFOs?

 

Thank you in advance,

Zouhair


Synchronisation PXIe-6361 and PXIe-4492

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Hello,

 

I'm trying to measure data with the two above mentioned cards in an PXI-Chassis (PXIe-1073) - the vi is attached.

Unfortunately I'm not a LabView specialist and the measured signals of both cards have a time offset of app. 5ms.

Can anybody tell me, how to synchronise the signals?

 

Thanks for your help!

 

Jürgen

Skipped frames in image acquisitio​n with 4 camera setup (2x 1430 cards), only recording approx. half the expected data

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Hi all,

 

I have a VI which sets up a continuous grab for four camera-link cameras at 100Hz (512x640).  I have the cameras running on an external 100Hz clock for synchronization (comes from NI DAQ box, trigger ports on the 1430 cards are not connected to anything).  The VI stuffs all the frames into a queue, and then I (slowly) have it written to disk after I acquire what I want.

 

The problem is, for a 4 minute capture, I only get around 14,000 items in the queue instead of 24,000.  Also, each image gets filled out with a buffer number, so I can see that it's not missing every other frame or something like that, sometimes it will skip 10 in a row, sometimes it will skip only a few... any ideas?

 

Here is an image of my collection setup (the write to disk part is not shown, but that empties the queue just fine) --

Thanks!  Sorry for the x-post I made a mistake and put this question in the hardware forum >.<

Mike

Synchronization of analogue input and analogue output?

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Hi there,

 

I have a signal synchronization problem:

 

I am sending two waveforms (i.e choice between sinus square triangle etc see attached VI) to a mechanical system and then I'm reading the acquired signal from this same system (and it should be similar).

The signal I am reading is indeed similar, however, the synchronization is not perfect. Whenever I changes the frequency of the signal the phase of the aquired signal is shiffting...

 

Does anyone have an idea how I should synchronize both send and aqcuired signal?

 

Many thanks,

Best,

Renaud

 

PS: I attached the VI in question 

sensor mapping with avi files

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Hello all,

 

I would like to bring avi movie file of a 3D rotation  and use sensor mapping vi. Does anybody have any suggestion.

 

Thanks,

 

Bob

Lego Mindstorm 2.0 SCCM deployment doesn't work

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Need help installing Lego Mindstorm 2.0 using sccm r2.

 

I am able to install manually but sccm deployment doesn't work using setup.exe with /AcceptLicenses "Yes" switch

 

Fatal error:

 

Required MSI directory peroperty Personal Folder is in an invalid location :c:\windows\system 32\config\systemprofile\Documents\".

 

I hope I am at right place..

 

Thanks

 

RJ

framed colour box colour changed randomly - using red, blue and yellow

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Hello

 

I want the user to do something when the colour box changes from black (ready) to green (set), and then Red, Yellow or Blue (go). The user wil know what colours are coming at them.

 

The user will will push a specific sequence of buttons according to colour.

 

Success will be pushing the sequence of buttons assigned to a specific colour. There are 16 push buttons. (this is for recall and reaction time)

 

Anyway, I can write the program no problem.

 

The user might do one trial of red (and push a specific sequence of buttons according to red), then blue, then yellow. I may get them to repeat a colour so they will do four trials.

 

Sorry for being long winded.

 

My question is how would I randomly generate a color to begin a trial.

 

So this set of trials is not known by the subject because on go the colour has been randomly presented as prompt.

 

Any help would be greatly appreciated!

 

Thanking you all in advance,

 

NK

Serially displaying multiple images in same picture box

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I am new to LabView, so please bear with me. I am trying to present a series of images into the same picture box on the front panel. I would like each image to appear in the box for 3 seconds and then disappear, followed by the next image after a 1.5 second delay and so on. I have 11 images that I would like to present in a pseudorandom order. 

 

Any advice would be greatly appreciated! I have tried multiple ways of doing this, and two of my failed vi's are attached. 


Labview error -1907 (sound and vibration)

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I am trying to measure two analog inputs(NI-PXI-4461) using daq assist on Labiew 7.1. I want to run the same code on both inputs and comparing them together on a graph. I am measuring 2 accelerometers and the most important parameters are measuring the g rms and phase difference. I keep getting an error code -1907 "The sampling frequency of the input waveform should be greater than 0 (dt greater than 0)." I have set the sampling freq to 2k. I am not sure what I am doing wrong. Any help will greatly be appreciated.

 

Thanks,

SparkEE

 

Block_Diagram.jpg

Controlling one vi from another (auto button pusher)

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The labview forums have been such a great resource, especially for someone that is not an expert level programmer like myself, that I thought it was just about time, that I tried to give something back to the community of people that have been so helpful. I just recently solved a problem that I would think effects lots of other industries, and that possibly many people have been in a similar situation.

 

We have a fully built labview program that tests a box that we have here. It is an actuator for the aerospace industry. But it could just as well be any other sort of electronic box. The labview code has been evolved for a number of years now, by many different developers, and is in a word AWFUL. It is just about the the most complicated and convoluted code I have ever seen. What makes it even worse, is that there is no documentation whatsoever. Imagine trying to fix the engine of a car, with no instructions as to how any of the parts are supposed to work, and you get the idea. 

 

The time has come in our developement process, that we want to start doing some automation. The main .vi has buttons and indicators that a technician will enter information into, send it to the box, and then wait for a response (part of a testing procedure). The code is not modular at all, and it would take a VERY long time, to attempt to re-write the code as it should have been written, in a more modular fashion. So what to do?

 

So I came up with a concept that I am calling "automatic button pushing". So basically what I did, was perform an Asynchronous VI call, to the VI in question, and then use various references and property nodes back to that VI, to push the buttons, and then look at the responses, as though I were a technician doing it manually. Clearly, this is not the most ideal solution. The proper way to do this, is to re-do the software so that things are more modular, and then probably use something like teststand to set up the testing for it. All of those things will happen in the future, but they needed something quick that can bridge the gap, and they did not want to touch any of the original code, as that would require re-certification etc. So what I proceded to do was to create a series of sub-vi's that touch all of the various buttons, and read the indicators that I need. Then string them together in a top level .vi to create a fully automated test. Enclosed is the subVI that I used to do the Asynchronous VI call, and an example of one of the controls that I am "pushing".

 

I am thinking this sort of thing might be very useful for others. Hope this is helpful..... :smileyhappy:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OOP architecture

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I have a sizeable application that I am trying to re-write into LVOOP and I am struggling with a architecture/design issue.  My current application uses a QMH design pattern and contains controls that simply start and stop various parts of the HW it interfaces too.  It contains a UI event handling loop, a UI event processing loop, various worker loops (acquire, process, and save data), and a few display loops.  I currently have coded up some of the UI event handling and processing using the command pattern in LVOOP.  What I am now struggling with is how to design and implement the worker loops/routines.  Basically, how do I design and launch my worker processes/objects using LVOOP?

 

I am envisioning creating classes for my HW (data acquirers), data processors, loggers, and displayers and have them work together.  I think I know how to create the classes, but I don't know how to launch them. 

 

As a simple example, consider a counter class.  How do I, from my main, top level UI, launch a counter object that counts in the background and report or makes available it's count back to the top level UI?

 

I apologize if the above is confusing.  I have done OOP before in other languages (Python, C++, Java), but I am completely new to LVOOP. 

Passing a boolean between loops

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Right now it would be my understanding, through experience, that labview won't less you pass a boolean between loop. For example, a while loop contains some code that produces and true boolean, and this while loop also contains a case structure with a for loop inside of it, so the for loop is nested in the case structure which is nested in the while loop. Is it correct that in labview you can't pass this true boolean to the case structure to execute the for loop? Or am I doing this wrong or in a way that harder than it needs to be? I'm new to labview, more similar with Java.

Master Slave Pattern with Events controlled by Joystick

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Hi Guys I want to control a Master Slave Pattern based on Events with a Joystick, because I could use this patter like a State Machine and so I can control a RC Car or something like that,  I think that the code is well because when I use a Button in the front panel the Event Case works but if I push a Button from the Joystick the Event Case doesn't works...

 

Could You help me, Please!

 

Best Regards!

 

^Oscar Abraham Sánchez.

SampClk.timebase.rate changes after Generation Task?

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I have a DAQmx Timing property node associated with a continuous AO task that pulls SampClk.Timebase.Rate each time before a new waveform (with different parameters) is created. After the waveform is created,  the task is started and stopped after data acquisition on other channels.  The weird thing is, there are instances where the value of SampClk.Timebase.Rate changes, even though nothing in particular changes the task properties except for the signals. I was under the impression that timebase rate is associated with the internal clock (NOT using an external clock here), and should be constant. Can anyone think of anything that could have caused this to happen? I am using a NI-4461, LabView 2010, and the latest NiDAQmx for this task, and SampClk.Timebase.Rate changes between 2.62144E+7 and  1.67772E+7 from time to time. Please help me explain this. Thank you!

 

 

Dan

Passing Data from application to hosted webservice on sbRIO

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I have a RT.exe running and am having a difficult time getting data from that application instance into my hosted webservices. There are two startup VIs running, and I can succesfully read the data between the two startup VIs, but I cannot figure out how to pass that data down to the hosted webservices. Some of the things I've tried are using global variables, queues, and functional globals and none have been able to pass any data from the startup VI#2 to the webservices successfully.

If you need more clarity to understand the situation, please feel free to ask me to elaborate on something.

 

Anyone else have any experience, or other ideas?

 

Thanks.


bluetooth discover VI dosen't work !!

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hi

I want to use bluetooth communication in LV 2013. in first step I want find other bluetooth machine in my local.

I use this Function buut it doesn't find any bluetooth device. I turned on my phone bluetooth but LV cannot found that !!

Thanks.

b1.png

How can I run RT code in development mode on ni 9068?

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This is my first time using NI 9068.

I set Disable RT Startup App in MAX and restart the RT, then click the RUN button on the vi. I saw the User FPGA 1 LED is flashing orange. I don't read any data the modules. I guess FPGA code not running.

Do I need re-deploy FPGA code when run in development mode?

 

Thanks for you help.

Feedback node in LabVIEW

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Hi everyone,

I am trying to simulate the second-order generalized-integral SOGI in LabVIEW and compare step by step with Simulink. The results are the same until I make two feedback loops by using feedback nodes. The graphs in LabVIEW show nothing. Can you give me some recommends for these iteration loop?

I attach SOGI and my simulation model for detail.

I really appreciate your nice help!

Best,

Tuan

read data from Serial communication with DB 9 and move cursor position

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Hi,

 

 I am doing a project using arduino board, i connected an xbee module to the board and db 9 cable from board to PC(windows). i am getting sensor values on hyperterminal of PC. Is there any way by which i can read the values from hyper terminal and do mouse operations.

Eg:   Suppose i receive letter L on hyperterminal i have to move cursor left

R- right

U-Up

D-down

C-click operation

 

Thanks

I cannot compile anything

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I have a problem with my setup. My labview project has been running perfectly till today, when I cannot compile any project. My project works perfectly in another computer. Same with "simpler" projects that I have. I cannot compile. I have tried to compile an empty vi, but the problem is the same. 
 
I decided to remove all labview components from my host computer. I removed everything from the host (NI-MAX/my-computer/sofware, all programs selected) and reinstalled Labview 2013. After doing that, the problem still happens. Attached you have a picture where you can check which error appears. It even happens with empty fpga VI.
 
I am running Labview 2013 in an Windows 7 64bit. Xilinx 14.4 13.0.0
My software package worked perfectly till today. Maybe something got corrupted...
 
Any suggestion? Thanks in advance
Pablo
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