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Polling Instrument Around System Exec

April 20, 2019, 10:42 pm
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Hi All,

I have a situation in which I am sending commands through cmd.exe to a DUT.  I need to poll a power supply's measurement function to see if the commands are affecting power consumption.  The requirement is to poll the power supply until the DUT's special state finishes, in which System Exec should finish executing.

 

I have created a timing unstable with possible race condition sample as follows:

Monitor.png

I am essentially software triggering a stop from the error node of System Exec, since it must output something when it finishes running.

Constrained to my limited hw setup (without a DAQ), what would be the better approach to accomplishing this task?

 

Best Regards,

mwc

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Create an Analog Output Instrument in Labview and use in Multisim

April 21, 2019, 4:52 am
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Hi, it's my first message on the forum and my english is not very good, sorry.

I've created an Instrument in LabView to use in Multisim and , the idea is to adquire waveform data from my sound card in real time and then send this data to Multisim to use the osciloscope, multimeter etc so basicaly measure this signal with minimum delay, I've tried to use "adquire sound" function and other examples I found on the forum but it doesn't seems to work...it simply sends data to multisim one time slowly  and after that the instrument doesn't update the new incoming waveform data so it stops , What I have on mind is to make a real time reaction instrument. do you have any example or tip to achieve that? I appreciate it very much. thanks!!! PD: Again, I'm so Sorry my English is really bad.

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State Machine Inquiry

April 21, 2019, 8:13 am
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Hello there , 

Guys now I have multi state machine " Four States " reference one and another three one and I want to access to any of the three state from my reference state to make a vending machine , as you can see in my uploaded pic , one more thing I want to know how to get a clock in this software to use it in my flip flop design . 

Thx in adv 

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Traitement de signaux

April 21, 2019, 12:43 pm
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bonjour svp je realise un electrocardiogramme sous Labview 2016 et j'ai des difficultés pour calculer a l'aide di signal prélever le nombre de battement pas minute.. J'ai trouver un document qui m'ai demander de détecter le nombre de pics(NP) et de faire 1000/NP pour avoir le nombre de battement..
j'aimerai avoir votre aide
voici le Vi

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traitement d'image

April 21, 2019, 12:48 pm
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  • bonjour svp je travail sur un projet sous LabVIEW de 2016 j'aimerai decomposer une couleur en % fonction des couleurs primaires, j'ai quelques pistes mais j'aimerai avoir un peu d'aide 
  • Merci
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Variant To Data Cannot Downcast VI Server Refnum

April 21, 2019, 3:21 pm
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I noticed the "Variant to Data" function does not work as one could expect when casting VI server refnums.

Indeed, if I have a refnum of a specific class (e.g. Numeric) that I upcast to a generic class (e.g. GObject), then feed it to the function to cast it back to a lower class (e.g. Control), it simply throws an error...

 

Variant To Data Cannot Downcast VI Server Refnum.PNG

 

Is it an expected behaviour ? I always thought "Variant to Data" just used the same behaviour as "To More Specific Class" / "To More Generic Class" when dealing with VI server refnums.

The upcasting however works fine...

 

The reason I am not using these 2 last VIs is because the input data I want to cast can be of any complexity (e.g. clusters that contain refnums AND non-refnum data), and the refnums may have been previously upcast.

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Sourcing vs Sinking Input and Output

April 21, 2019, 4:42 pm
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Hello,

 

I need help deciding if I need a sourcing or sinking input and output digital card.  I have a snippet from my IAI manual attached. I have the NPN option on the cylinder. Could someone help me decide on which input and output card to get? It appears i should have a sinking digital output card and a sourcing digital input card but I wanted to confirm.

 

IAI cylinder.png

 


IAI cylinder II.png

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labview GPU FTT of a 8bit 650x650 grey-scale image

April 21, 2019, 5:18 pm
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Hi,

 

I'm looking for an example on how to use the labview GPU toolkit to compute the FFT of an 8bit grey-scale image.

In the attachment you will see that the FFT is not happy with its input.

 

Can somebody provide a simple example on how to do this?

 

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Linx Arduino to Arduino I2C Communication

April 21, 2019, 7:37 pm
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I have two Arduinos. One of these Arduinos is master (COM6), the other is slave (COM3). 

 

Master.ino

 

// Source: https://www.instructables.com/id/I2C-between-Arduinos/

#include "Wire.h"

int val = 99;  // value to be passed to other Arduino

void setup() {
  Serial.begin(9600);  // begin serial 
  Wire.begin();  // begin i2c
}

void loop() {
  Serial.println("Pass the value of val to another Arduino");
  Serial.print("The value of val: ");
  Serial.println(val);
  Wire.beginTransmission(9);  // begin wire transmission on 9
  Wire.write(val);  // write the value of val over port 9
  Wire.endTransmission();  // stop i2c
  delay(2000);  // wait 2 seconds
}

Slave.ino

 

 

int x = 0;
void setup() {
  Serial.begin(9600);
  Wire.begin(9);
  Wire.onReceive(recieveEvent);
}

void recieveEvent(int bytes){
  x = Wire.read();
}

void loop() {
  Serial.println(val);
  delay(1000);
}

The serial monitor for the master. 

 

Master_serial.PNGMaster.ino Serial

Serial for the Slave. 

Slave_serial.PNGSlave.ino serial

This means this I2C code works.

 

Now for LabVIEW... 

Setup Arduino using LINX. 

Linx_Uno.PNGselect uno

Linx_become_Slave.PNGslave is com3

The block diagram.

Save_block_diagram.PNGblock diagram

LabVIEW successfully running with no data. 

No_data_to_slave_9.PNGno data to 9No_data_to_slave.PNGno datat to 0

 

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AutoIT Keypress Unstable

April 22, 2019, 12:45 am
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Hi all,

I am trying to create a program to help me book a transportation through a website.

In order to automate the process, i use AutoIT to help me complete the key press and complete the booking.

 

However, i found that the AutoIT keypress send is sometimes unstable. For example, when i want to press down for 3 times, i send {DOWN 3} but what i have seen is it clicked 16 times instead of 3 sometimes.

 

I have attached my source code here. Can anyone please advise on how to avoid this condition from happening? Thanks in advance.

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change the color of square LED boolean

April 22, 2019, 12:52 am
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As title, I want the color of off form is transparent, but it does not display as my expectation.

 

I tried to use color 4 of property node, but I fail.

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Re: Save & Recall setup

April 22, 2019, 2:41 am
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Good afternoon to all,
I am a new user to LabVIEW Robotics 2017 and I have recently started writing my first program. However, I have faced some issues along the way. Firstly, I am unable to recall the saved setup from the oscilloscope as show in both the Image (1) and Image (2) below. 
In image(1), I am directly using the command : RECAllSmiley FrustratedETUp and I have followed the instructions as stated in the programmer manual, yet there are still errors popping up, as shown in error (1). In image(2), I used the current VI path function to obtain the path name, followed by strip path and build path to get the ideal filename, then after that wire straight to VISA write. Same thing, errors still popped up as shown in error (2).
If there is anyone who has done something similar or who has knowledge of this, I will greatly appreciate your help and advice.
Thank you! 


 

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trucker line interface

April 22, 2019, 3:32 am
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I want to do a robot interface supervision, and I want to draw the robot trajectory in the interface and see the robot's move,Idon't know how to start

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Labview: memory is full Error

April 22, 2019, 4:02 am
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I am performing an impact test for which I am acquiring data using LabView 10. I am acquiring data @ 1Msamples/sec. for 4 seconds. When I am acquiring data for 2 sec, the program is running fine but when I am increasing data acquisition duration is showing following Error-

 

Labview: Memory is full

The top-level VI "test-1.VI" was stopped at unknown on the block diagram of "ex-CreateSignalChunkString.vi"

refer to the VI Memory usages topic in the LabView Help for suggestions on monitoring and improving VI memory usage.

 

I am not using any loop/ structure in my program. I am just acquiring analog voltage data from the strain gauge and writing it to measurement file (.lvm).

I would be thankful if you can suggest me the required modification in my program.

 

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Trigger Event through file path control

April 22, 2019, 4:11 am
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I've noticed a undesired action stemming from a file browse window.  When the file browse window is open over the control area, it triggers an event for the background front panel control.

 

I attached a little demo .vi, which shows the behavior.

 

Is this an intended Labview action, and any ideas on avoiding it?

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selling exe file

April 22, 2019, 4:40 am
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My company is looking into using LabVIEW to build an application that will be sold as part of a product.  The product would have the executable file installed before shipping to the customer.  Is this permitted given the licensing agreement or is there some other licensing required?

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Continuous Measurements in I2C (USB8452)

April 22, 2019, 6:24 am
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Greetings,

I am a newbie on LabVIEW, therefore I would like to apologize for any obvious question or mistake that you may found in the vi. I am trying to commuinicate with a hall effect magnetic sensor (AK8963) by I2C using the USB 8452. I am able to cummunicate and wirte in all the registers, however, I am unable to measure continous data from the sensor. I have to press continous measurements, then stop, then play in order to get different values at diferent times. Hence, I would like to ask for any help in order to measure and write on the registers in a continous manner. 

 

I would to thanks in advance.

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Square waveform to Boolean for Binary phase shift keying

April 22, 2019, 6:33 am
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Hi, 

I'm trying to convert a square waveform to logical true or false pulses which are used to change the phase of a sine carrier waveform by 180 degrees for each logical change. The desired output should look something like this.

desired.PNGDesired Output

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

However, with my current setup I'm not getting what i'm expecting. Is my square wave to Boolean setup wrong? 

I seem to be getting only a True value out of it. Any help would be greatly appreciated.currentoutput.PNGCurrent Output

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


currentvi.PNG

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Simulate Signal Express VI over generation problem

April 22, 2019, 6:58 am
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Hi everyone, 

I'm building this Simulate signal VI to generate waveform within a dedicated period of time determined by Elapsed TIme express VI both in the same loop. So that I can control exactly the output signal period for further application. 

Waveform generator.png

For instance, the simulation signal period is 6s and time elapsed for the while loop to run is 3s, therefore I should always obtain 1/2 period signal generated when the while loop terminated. But somehow, the Simulate signal express VI is by chance over generate extra 1 point that ruins the expected output signal. 

2-horz.jpg

Please help me to fix this,

Thank in advance.

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Traitement de signaux

April 21, 2019, 12:43 pm
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