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Programmatically detecting Plot Visibility Checkboxes in LabVIEW

March 9, 2020, 7:31 pm
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Hi everyone,

I have a question regarding a part of a program that I'm working on which is about capturing data from an oscilloscope.

 

The program needs to be able to capture multiple analog signals from multiple channels of the oscilloscope and get the waveform characteristics such as rise time, frequency, peak to peak etc.

 

The displaying of multiple waveforms on the graph is achieved through enabling all channel inputs and using Plot Visibility Check boxes.

 

What is required now is to know which plot(s) are enabled so that their waveform characteristics can be displayed.

 

My goal is to identify the enabled plot(s) and display the data accordingly.
e.g. When Channel 1 is checked, only the data of Channel 1 should be displayed and the data of Channel 2 should display 0. And vice versa.
Additionally, when both Channels are selected, data of both channels should be detected.

 

In order to achieve this, is there a way to programmatically detect the action of Plot Visibility Checkboxes?
As in, is it possible to programmatically know which plot is displayed on the waveform graph?

If there is any alternative method to get the same result, please let me know. Your help would be appreciated.

 

I have attached the segment of code relating to this issue.

 

Software, Drivers and Equipment used:
* LabVIEW Ver.2015
* Agilent 2000 3000 X-Series Driver
VISA Resource Name: USB0::0x0957::0x17A4::MY53160161::INSTR
* Agilent Technologies DSO-X 3034A (Keysight Technologies) Oscilloscope
* SG1638B 2Hz-2MHz Function generator
* Toshiba Windows 10 PC

 

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Input string problem

March 15, 2020, 10:32 pm
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Hello every !

I have a script want to change the contents with front panel but after switching it turns to wrong form as the picture... 

here is my front panel and program and hope someone can help my problem ….

A.PNGB.PNG

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Error with standrd icon while building application

March 15, 2020, 10:37 pm
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Hello, LabVIEW community!

I've got a strange error while trying to build an app: error related with default icon association to my app.

I'm not an expert with LabVIEW ... still this seems strange to me (I'm running LV under admin rights; this icon is actually in place; I've tried to point to another icon in build options but get the similar error message)...

Could you, please, advise what is this attributed to and how this could be resolved?

Thanks,

Greg

image.png

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Fail to update all feeds

March 15, 2020, 11:32 pm
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hello,

error "fail to update all feeds" occurred when install "ni-labview-2019-runtime-engine-x86_19.1_online". error details as shown below

Failed to update all fields.
Visit ni.com/info and enter the Info Code NIPMCommError for more information.
Additional error information:
An error occurred while trying to download the feed:
http://download.ni.com/support/nipkg/products/ni-package-manager/released/Packages.gz

Here is the screenshot
2020-03-16_13h41_19.png

 

I found that the link can only access to "http://download.ni.com/support", there is no "nipkg" under the "support" tree. (see sreenshot below). so how to solve this problem? the right link is?

 

123.png

 

thank you!

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Edit Map Constant and Set Constant

March 15, 2020, 11:56 pm
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Collections is a great feature recently added to LabVIEW. However there are simple practical questions. Probably I am too bad internet searcher, so please answer.

 

Map Constant or Set constant contain no data when placed in BD from palette. However, data-containing indicator can be converted to data-containing constant. Thus constant can contain data.

 

I cannot find a way to edit such a constant directly in BD. The values are not accessible with any tool. Please advise how Map Constants and Set Constants can be edited?

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using HMI/labview to design automatic drip irrigation system

March 16, 2020, 12:26 am
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Hi, every one 

I'm working to design a monitoring automatic drip irrigation system, my Q. is can I use HMI/Labview to control and monitoring this system???. And how I can do that? please help. 

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VISA miscellaneous error

March 16, 2020, 2:41 am
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Hello,

 

I use VISA pallete VIs to communicate with my device (KIKUSUI HV tester equipment)

When I start a test, I will Open VISA reference and at the end of test, I will Clear and Close the VISA reference.

I go back to another screen and again come back to start test, I get VISA error. Error number is -1073807360 which Unknown miscellaneous error on VISA.

Then I have to quit the application and reopen the application to run test again.

Is there any way to close all VISA references?

This error does not occur every time but happens randomly.

Mostly, I get error when I exit the test screen after closing VISA reference and come back to test screen by opening VISA reference again. At this point when I open reference, I get error.

Thank you

Hema

 

 

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Analytics & Machine Learning Toolkit

March 16, 2020, 4:54 am
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I don't find any AML Toolkit installers for LabVIEW 2019. Is there any option that I can Instal AML for LabVIEW 2019.

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How can I remove time delay in my motor control system?

March 16, 2020, 6:34 am
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I have a system which control the AC motor.

 

I make the code of FPGA and use it in the RT code.

In FPGA code, I make the pulse and read encoder pulse by using while loop.

 

But, when I run this system in my code, the result show the time delay.

 

I'm not sure that the reason of delay is my code.

Is there some problems in my code?  

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Best practice for timer during measurement?

March 16, 2020, 6:39 am
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Hi, I have a DAQmx read vi that is measuring for several seconds. I would like to have a front panel indicator to show the user the remaining time. This requires a parallel loop that handles the timing. I made something that works using notifiers (don't worry about the DAQmx part for now):

Timing practice.png

 

So the DAQmx read and the timing loop start at the same time. The loop waits for a notification for 500ms, updates the indicator and runs again if no notification is sent, which is the case while the measurement is running. Once the measurement is finished it sends a notification to the timing loop and after a maximum of 500ms the loop ends. The loop also ends if the timeout of the DAQmx is reached (I simply set this to be 2 times the measurement duration, this can be any factor).

 

Though this works quite well, I'm still learning LabVIEW and I would like to know if there are other, better or more common solutions to this.

Thank you very much in advance.

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request an example for adjustable analogue clock by needles

March 16, 2020, 7:04 am
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hi 

i have found a lot of analogue clock examples but thing that i want is adjustable analouge clock which I can adjust time via needles to set hour , minutes and second in example in the file attached on 00clockmainUI i want to make the clock adjustable via spinning needles by the user.

does any one has a proper example?

thank you

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Radio buttons all connected to property nodes

March 16, 2020, 7:11 am
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I want to connect each radio button to a property node so they all get updated at once.

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Cannot change the color of a Tab control

March 16, 2020, 9:56 am
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Hi. I have a tab control that I would like to change the color of manually using the paintbrush but it won't let me. When I right click with the paintbrush over the Tab control, I get no color palette as expected. If I move the brush off the Tab, over the background, and right click, the color pallet appears and I can change the color of the screen background. If I place controls or boxes on the Tab, I can change their colors as well. If I place a new tab control from the menu, it behaves normally. I can color it with the paintbrush just fine. I have tried to change the color programmatically using a property node, but I get error 1131; "You cannot use this property with this control". I tried changing several different properties programmatically and always got this same error. The program was originally written with LabVIEW 2016 by someone else. I am trying to make a few changes using LabVIEW 2019. The reason I don't just replace the Tab control with a new one is there are over 100 controls and indicators on the 5 tabs along with many boxes that would need to be moved and repositioned.  Any ideas?

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Threshold detector PtByPt - negative threshold

March 16, 2020, 10:36 am
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Hello, I am using Threshold detector PtByPt to detect a signal that goes from 0 to -90. I set my threshold to -50 but the detector doesn't detect it, is there a way to negate my input signal or change the "internals" of the Threshold detector PtByPt .VI so it can detect?

 

It is a waveform signal that consists of Y, dt and t0. I  tried to negate but nothing happened. 

 

Thank you for any advice.

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daqmx Available Samples Per Channel not zero

March 16, 2020, 12:23 pm
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cDAQ 9178

When you monitor the Available Samples Per Channel in the DAQmx Read and it is not zero what does it mean? Does it mean samples were available that didn't get read? Sampling at 10,000 hz and taking 2000 samples per channel. The loop should run at 200 ms and there should be zero samples available to read, correct? I am seeing available samples using a simulated chassis and modules. I haven't tried reading this on the actual hardware, don't know if that matters.

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Charge and discharge 18650 cell

March 16, 2020, 1:00 pm
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Hi,

 

I am trying to create a VI which will charge a cell from 2 volts to 3.5 volts then discharge from 3.5 volts to 2 volts and repeat this process for a specified number of iterations. 

 

I have a vi where I take a voltage measurement from a DAQ6008 and pass this into min max and then into a case structure which then depending on the max min is either true or false (note the max min is the 2-3.5 volts) therefore if the voltage is in this range the output should be true therefore turning on the keithley 2000 power supply. 

 

 My problem is how do I now if im charging or discharging as it should be always in the specified region 2-3.5 volts. The range wont change and if its always in the range its always true and always turning on the power supply. 

 

I have attracted the VI (2014 sp1)

 

All the best

Darragh

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Running Two Velmex Motor Controllers Simultaneously

March 16, 2020, 1:16 pm
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Hi,

 

I am trying to synchronize the movement of two stepper motors which are each connected to a Velmex controller.  Currently, I am having difficulty with the second while loop even though it is identical to the first while loop.  If anyone could help me troubleshoot my VI, I would really appreciate it.  Thanks!

 

 

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Python and Excel

March 16, 2020, 1:50 pm
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I try to read an Excel file (.xlsx) and return an 2D Array of string to Labview. 

 

To verify if I am able to correctly read the file:  I read the file and write a CSV file from the original Excel file - this part works even if I have an error (Python returned the following error: <class 'SystemError'> ..\Objects\listobject.c:189: bad argument to internal function).

Python 1.JPG

 

The script is:

 

import pandas as pd

def MyFunction_Excel(path1, path2):
    dfs = pd.read_excel(path1)
    dfs.to_csv(path2)
    return dfs

 

 

I am not able to return the 2D Array.  What I am doing wrong?

 

JM

 

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Polynomial LabView

March 16, 2020, 5:03 pm
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Using MathScript create a VI that computes and plots the second-order polynomial y = Ax^2 + Bx + C. The VI should use controls on the front panel to input the coefficients A, B, and C, and also should use front panel controls to enter the number of points N to evaluate the polynomial over the interval x0 to xN-1. Plot y versus x on a waveform graph indicator

 

Thank you

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Shore Western Actuator Input and Output exchange with NI cDAQ

March 16, 2020, 6:06 pm
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Hi, I have a question regarding the hardware connection, I am using a Shore Western Hydraulic Actuator for my test and it has its own controller (attached its hardware configuration) and I figured out that I need to sync it with the DAQ (NI cDAQ-9178) in order for both to have the same clock (same time during the test). Also I need to have one of the voltage reading from the DAQ (one coming from a wire potentiometer) to be also shared with the actuator controller as a feedback. I am using LabVIEW NXG for the DAQ Is that doable ?
 
I would really appreciate your help on this matter.
 
Thanks
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