Quantcast
Channel: LabVIEW topics
Viewing all 67066 articles
Browse latest View live
↧

Need to build FPGA bitfile twice

June 24, 2018, 6:57 pm
$
0
0

When I build my cRIO/FPGA project's FPGA build specification into a bitfile, the output immediately complains that the bitfile doesn't match (and the project has the dirty star mark).

 

If I try to close the project, I'm told that an item was added, an item was moved, and an item was removed.

 

Building a second time (without making changes) results in a happy project. Alternatively, (iirc) I can change the Open FPGA VI Reference to reference the specific bitfile, and all is well (it's currently referencing the Build Specification).

 

The RT subVIs make use of the bitfile via a typedef to the reference, which also targets the Build Specification.

 

Opening two of the FPGA VIs' windows then closing them immediately result in the project having changes (the same Added, Moved, Removed combination). These are the top-level VI, and the VI (called by the top-level VI) that does most of the work (SPI communication).

 

Is there something obvious I'm messing up here? The bitfile appears in the RT Dependencies, but nowhere else that I can see.

↧
Search

Narrow band analysis

June 24, 2018, 10:28 pm
$
0
0

We are working on delivering an underwater acoustic signal acquisition and analysis project, the main components of which are running LabVIEW.

 

Towards acceptance trials of one analysis, namely, Narrow Band Analysis (NBA), we suggested the following test taking into account a model frequency of 10kHz which will be generated by signal generator, processed by PXI controller and analysis done by a PC running LabVIEW:

 

Set the input frequency at 10kHz and amplitude at 5V peak to peak with below parameter setting:-

* Sampling frequency at 260kHz

* Low pass band 100 Hz

* High pass band 100 kHz

 

The verifiable result given by us was : Amplitude of 2.5V, at 10kHz  frequency, is displayed after FFT.

 

The client has commented that the test is both inaccurate and incomplete.

 

Can anybody suggest the problem and way ahead. We have limited knowledge of signal processing.

 

Thanks and Rgds

↧
↧

How to _permanently_ sort .lvlib/.lvclass contents by Type?

June 24, 2018, 10:30 pm
$
0
0

In the LabVIEW Project explorer, we can right-click -> Arrange By (Name, Type, Path, Custom). However, I cannot seem to save my choice. When I close and re-open my project, it reverts to Arrange By Name. Tested on LabVIEW 2017 SP1.

 

In contrast, Targets (e.g. "My Computer") and Virtual Folders outside .lvlib/.lvclass files can be permanently sorted.

 

Am I missing something?

↧

beginner need help

June 24, 2018, 10:32 pm
$
0
0

Hi everyone,

I just start learning Labview, how can i write a while loop to do a = a +1 and this loop will stop when ''a'' equals a certain number?

I know this is pretty silly question but i can not do it since labview is unlike other programming languages, it has numeric control and numeric indicator.

Thanks for your help

↧

How to find the multisim vi in labview?

June 24, 2018, 11:54 pm
$
0
0

Dear NI family,

 

I am using the co-simulation function in NI Multisim to build a new VI based on the circuit design in it. However,

When I open labview, I can't find the VI in the software.

 

I am using LabVIEW 2016 and  Multisim 14 and as the help says"LabVIEW Multisim Co-simulation

For LabVIEW Multisim co-simulation to function, LabVIEW 2015 or 2016 (32-bit) is required"

 

I have put the LabVIEW Multisim Co-simulation/Labview/Multisim in the same directory.

Please give me some advice on how to find the vi.

 

Thanks.

 

Best,

Jason

↧
↧

Loading a LabVIEW Built Application (EXE) into a VI Front Panel

June 24, 2018, 11:55 pm
$
0
0

Hi 

 

We have a use case where we have to load a LabVIEW Built Application(EXE) in VI Front Panel.  Can anyone suggest how to do the same in LabVIEW?

↧

Synchronizing states across multiple loops

June 25, 2018, 12:34 am
$
0
0

Hello, newbie here. I am trying to find a way to synchronize states across multiple loops. I have a number of loops that run in parallel at different rates. During each iteration some of them can change state and others have to change what they are doing depending of them. Some loops are both "consumers of states" (meaning they read the state of others and behave consequently) and "producers" (meaning they set states). 

 

I need a compact and scalable solution that can handle multiple producers and multiple consumers of states and is easy to modify if I need to add a new loop. So far the best solution I have found is storing states into enums and using local variables to read them in consumer loops; however, I read everywhere that local variables should be avoided. 

 

A Queued State Machine seems similar to what I need but it seems optimized for one consumer, whereas I need many of them. I tried using notifiers but they are only useful when changing states, not for storing them, because every Wait on Notification sees the new state only once. This forced me to add a shift register to store the content of the latest notification, but this seems overly complicated and needs a lot of wires and case structures which can be avoided using local variables.

 

I attached to this post an example VI. This is very general and the content of each loop is simplified compared to what I need. However it should explain my problem. Loop A changes state during each iteration. Loop B is a pure consumer of Loop A states. Loop C is both a consumer of Loop A states and a producer of its own states that Loop A checks in the second part of its iteration. Imagine that there are many other loops like these, and they communicate states between each other. 

 

What's the best way to handle this synchronization issue?

↧

how to limit Chart History in XY graph

June 25, 2018, 3:22 am
↧
Search

Multiple channel configuration along with scaling

June 25, 2018, 4:17 am
$
0
0

Hi everyone,

 

my program is regarding multiple cahnnel configuration using cDaq and NI9203 

Please fingdthe program attached.

Problem is I´m unable to run the program without Setting the tast terminal. So connected a Task terminal, but then it didnot work untill selecting a Task. After selecting the Task, as expected it works according to what has been already configured in Task. 

Please suggest me how to correct this and be able to configrue each channel

 

Thanks a lot in advance

 

Best Regards,

Deepa 

↧
↧

Error 56 (Timeout) on Modbus RTU read

June 25, 2018, 5:19 am
$
0
0

Hello,

 

Our program has been running on a cRIO for a while, reading data using Modbus RTU (Modbus VIs from DSC Module / Real-Time Module).

Suddenly all modbus instruments stopped giving data. I'm getting a timeout on all read calls.

 

Tried restarting, etc., reading only from one instrument, but nothing helps.

Open MAX and try "Open Visa test panel" on the device, but this gives a message:

 

Error opening resource:
visa://123.234.345.123/ASRL3::INSTR

VISA:  (Hex 0xBFFF00A7) The remote machine does not exist or is not accepting any connections. 
If the NI-VISA server is installed and running on the remote machine, 
it might have an incompatible version or might be listening on a different port.

This tells me it's probably not the code, or the physical instruments (since none of them are working now), but something with VISA in general ?

 

LabVIEW 16, with corresponding VISA 16. Note that this worked well until recently.

 

Any advice how to proceed with solving this VISA problem?

↧

Sync Daqmx AO with AI

June 25, 2018, 5:51 am
$
0
0

Hello Community,

 

I'm generating a control signal and I would like to write this signal to an AO while simultaneously read the response on an AI. All the AI and the AO channels are on the same PXI board. One of the AI channels is a loopback from the control signal, so I can verify if everything is properly written. 

 

If my AIs and the AO are truly in sync then I would expect that the loopback signal within my acquired signals look always (very-very-very much) the same. Instead of this the AO slightly changes its position and this could be as high as about 1-2ms, so I guess the AIs and the AO is not properly synchronized.

 

I'm pretty sure I have just messed up something in my code, would you mind checking it and letting me know whats wrong?

Thanks.

 

 

 

 

daq.png

↧

Image Processing

June 23, 2018, 5:02 am
$
0
0

The Program is running almost as intended; for some reason the outputs "New Picture 3" and "New Picture" appear as an "aqua-scale" but the intended result was a gray-scale. And I really dont know where my coding went wrong; I am still learning and would be very grateful If someone could offer some assistance. I attached the VI and an example image to be used as input. I attached the image as jpeg but it should really be a BMP (The website does not allow BMP files)

Thanks in advance

↧

Newbie question about storing data

June 25, 2018, 6:45 am
$
0
0

I would like to create an AI data holding area, say, Buffer3000. It will store 3000 data. I will read 1000 AI numbers a second, store them in Buffer3000, take the average of the buffer, display the average. This process will be continued throughout my test. New 1000 numbers will be added, and old 1000 numbers will be pushed out. 

 

How actually do I do this? Thank you.

↧
↧

Call Library Function Node in Test.vi

June 25, 2018, 7:17 am
$
0
0

Hi Guys,

 

I am really new to Labview.

I am strugling to configure the VI as shown in the uploaded pics.

I am basically trying to access the DLL library with Call library fucntion.

the calling function is

int16_t WriteFPGARegsC(int16_t *USBdev, int32_t *DUTSelect, int32_t *Array_RegsIn, int32_t *Array_RegsOut, int32_t *Array_RegEnable);

 

Array_RegEnable is supossed to be initialised with an array of 255.

while Array_RegsOut and Array_RegsIn are output or indicators of array of 255.

I am getting error code 12 with message 'Call Library Function Node in Test.vi' when i execute the test.vi

Please give me some advice to solve this issue.

 

Thanks & regards,

Kushal

 

 

↧

Where is Compound Arithmetic function in NXG

June 25, 2018, 7:17 am
$
0
0

Hello,

I am trying out LabVIEW NXG and cannot find the Compound Arithmetic function that I have used in other, older versions of LabVIEW.

It's not with the Boolean functions where I expected it to be. I searched and searched other pallets.

Thanks.

↧
Search

Programmatically Update Combobox Getting Duplicates in LabVIEW

June 25, 2018, 7:38 am
$
0
0

New to LabView and am using 2017 version.  I have a combobox that is already populated with items and a user will be able to add to the combobox items by entering a new string value and pressing a button.  The button is in an event structure which is inside a while loop.  The problem is when the new string value is updated in the combobox there are two.  Is there anything that can be done to prevent the duplicate?

 

Thanks

↧

Reading multiple cDAQ9213's

June 25, 2018, 7:46 am
$
0
0

Hello all,

 

My project is to create a graphical representation of temperature points inside of a box.

So far I have 4xcDAQ9213's wired up and functioning properly.

The part where I'm kind of stuck is finding an efficient way to set up all these channels(64).

I could set them up 1 by 1, but this is rather time consuming and I have a hunch there is a better way.

 

I want to be able to display each individual channel on the front panel to mimic real TC points inside the box showing their temperature in real time.

So far this is the code I have, there is a lot of useless reduntant bits please ignore those if you can. Thank you

Spaghetti bowl.PNG

↧
↧

Exporting Data to Excel From While Loop

June 25, 2018, 8:14 am
$
0
0

Hey Guys,

 

So I have a while Loop that is collecting data from a myRIO and running it through some formulas. There are 5 Analog voltage signals in all. What I would like to do is pass this data onto a spreadsheet in 6 columns. The first column being the time and the other 5 being the signals. What would be the best way to do this? Can I just build an array out of the 5 signals and the time and print that to a spreadsheet? I am pretty new to labview so thanks for your help.

 

Thanks!

↧

VLA, serial numbers, and activation: how do they work?

June 25, 2018, 8:18 am
$
0
0

Our group recently purchased a VLA of LabVIEW so we could upgrade from 2013 to 2017. Our IT administrator installed the NI VLM on a server, and I upgraded all our clients. When I point each machine's License Manager to use the Network License, it picks up the license, but when we use LabVIEW it opens in Evaluation Mode. If I manually Activate the VLA serial number on each machine it a Local License and we can use LabVIEW normally.

 

If I need to manually activate the serial number, and LabVIEW uses the Local License anyway, then the Network License, and VLM seem useless. What am I missing? Probably something simple, but I just haven't seen it yet.

↧

FlexRIO High Throughput Scripting/Memory question

June 25, 2018, 8:25 am
$
0
0

Hi,

     I'm using PXie-7966R with 6581 Module and I am attempting to run sequences of large patterns from memory but seem to be running into a speed bottle neck with the DRAM. Basically I want to output vectors from memory to output pins. Base on triggers or stimulus on input pins I which to run different parts of a memory sequence. I want this to be pretty flexible so I can load new patterns to memory, provide start pointers and length counters to the FPGA then get the FGPA to run the sequence base on some logic I can set.

    As a starting point I was trying to run a core SCTL at say, 400MHz and run a pattern at that rate (e.g. a simple AAAA,5555,AAAA,5555.. at first just to check I could run at that speed.)

    As my patterns for memory will be large, and need to repeat in many cases, based on triggers or responses, I don't think a FIFO is suitable. I have been trying to use DRAM but seem to be limited into how fast I can access the DRAM. Is there a suggested way to e.g. pipeline the DRAM to Output at say 300-400MHz? Or some other way I could get the data from memory out to pins on the module?

     Thanks,

       ds1 

↧
Viewing all 67066 articles
Browse latest View live
Search
<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>