I am working on a project that requires capture of motor shaft movement. The Shaft movement is monitored and data acquired through two proximity probes which are 90 degrees apart for X (horizontal movement) and Y (vertical movement) shaft movement capture. The proximity probe distance range is from 0.25mm (0 Volts) – 1.25mm (10 Volts). So when the proximity probe is less than or equal to a distance of .25mm between its sensor and target object, the voltage out is 0V and when the target distance is 1.25mm or above, the output is 10V. The proximity probes are connected to AI module N9221 whose voltage range is +/- 60V sitting in NI- cDAQ-9174 chassis. The acquired voltage output of N9221 is converted to distance and should be used for orbit-plotting in LabVIEW. I have acquired and converted output signal of N9221 but now need help on how these data can be used for LabVIEW Orbital plot?
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LabVIEW Orbit Plotting of acquired motor shaft movement Data
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Differenze between two consecutive peaks to calculate the period of a signal
Hello guys, I'm doing a program (for my research activity) which it's supposed to calculate the distance between two peaks of a signal (in order to find the period) while the window is scrolling. I'm new to labview actually and I read all the previous discussions of this topic but I can't seem to find a solution. Here I am attaching the vis so can you please help?
Thank you in advance.
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Ni Compact RIO install
Hi all,
I might be missing something here but I am trying to install NI CompactRio Device Drivers January 2019 and I am not able to select where I would like to have this installed (appears to be grayed out). I cannot install it to the default C drive as I simply do not have anymore space and I am unable to free up any more space. Does anyone know how I can change the default install directory ?
Thanks,
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Increase the data acquisition points
Hi there,
I am using labview to acquire a waveform from a RIGOL DS4024 oscilloscope. Even though I have set the oscilloscope's memory depth to more than 7000 points my appended array in labview acquires only 1400 points. I am willing to get more points. However when I tried to change the WAV:MODE NORM; to WAV:MODE RAW; I still get 1400 points. Any ideas on how to increase the number of data points acquired?
Thanks in advance!
Regards,
John
P.S. I attach both my main and my read programmes!
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PID control with sensors and actuator
Hi,
I am doing a project which has been mechanically set up such that when a linear actuator moves up, the force exerted on the sensor increases, and when it moves down, the sensor reading decreases.
I have a VI that takes data readings from sensors (PV) and compares it with a desired value (SP).
Based on that, my PID control is supposed to send a command to the linear actuator to move up or down such that it reaches the SP and maintains it.
I am unable to figure out how to convey information between the PID output and the linear actuator input (i.e. if I probe the PID output, it shows a value of 100 when the error is 0.7N; but how is the actuator supposed to know what 100 means?)
I am new to controls and LabVIEW, but am I missing something subtle here?
Please let me know.
Regards
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Button permanently in keyboard focus
Hi all,
just as I thought I've seen it all, this happens.
I built a user interface with some setup information as well as a button to connect/disconnect.
After that the user can enter command in a line. The line is a system string control set up for single line and also update while typing to trigger a value change event.
Here's my problem: When I hit enter, the keyboard focuses on the Connect/Disconnect button and disconnects my application.
What I've tried:
- reordering the tabbing order
- adding a key down event
- clicking on other buttons before writing in the string
The behavior I want is:
Enter text in string, press enter --> trigger string value change event
not focus on and press connect/disconnect button
ideally, keep focus on string, so the next command can be entered.
VI is attached it's written in 2012.0 f1.
I am grateful for all pointers and moral support in these trying times...
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How to change sampling rate?
Moved to another board
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Rich Text Box Example
I'm trying to run a C# Rich Text Box example from https://docs.microsoft.com/pl-pl/dotnet/framework/wpf/controls/richtextbox-overview. The idea is to inline bold text in the rich text box.
I was able to rewrite all the code in LabVIEW except the last line: this.Content = myStackPanel;
Can I ask for help with reviving this example? How to get rich text box on the LV front panel and how to inline bold text?
C# below
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Documents;
namespace SDKSample
{
public partial class BasicRichTextBoxWithContentExample : Page
{
public BasicRichTextBoxWithContentExample()
{
StackPanel myStackPanel = new StackPanel();
// Create a FlowDocument to contain content for the RichTextBox.
FlowDocument myFlowDoc = new FlowDocument();
// Create a Run of plain text and some bold text.
Run myRun = new Run("This is flow content and you can ");
Bold myBold = new Bold(new Run("edit me!"));
// Create a paragraph and add the Run and Bold to it.
Paragraph myParagraph = new Paragraph();
myParagraph.Inlines.Add(myRun);
myParagraph.Inlines.Add(myBold);
// Add the paragraph to the FlowDocument.
myFlowDoc.Blocks.Add(myParagraph);
RichTextBox myRichTextBox = new RichTextBox();
// Add initial content to the RichTextBox.
myRichTextBox.Document = myFlowDoc;
myStackPanel.Children.Add(myRichTextBox);
this.Content = myStackPanel;
}
}
}
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Labview Upgrade
I am currently working on a Senior Project where my team and I have acquired a 6 degree of freedom medical testing device. The hardware consists of NI PCI735x and MID 7654, two components that are now obsolete for NI. The code has a lot of issues and was written in LabVIEW version 8. If we decided to upgrade our LabVIEW version to the most current would the Hardware need to be updated as well?
Thank you in advance.
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時間を表示
写真のVIはY=0を交差した回数を出すものとなっております。このVIから交差した時間を出したいと思っているのですがうまくいきません。誰か教えてください。お願いします。
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File and channel selection
Hi all! I am new here. Right now, I have thousands of tdms file. Each of the tdms file have four channels and each channel can displayed in waveform graph.
The problem is I dont know how to bulid a listbox which u can choose the file from and another listbox to select the channel.
Appreciate your help!! THX
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時間を表示
Moved to japanese board
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temperature acquisition
Hi I wanted to ask and receive information about a system consisting of a voltage divider and a data acquisition card NI USB 6000. After running the circuit using LabView 2016 the values that appear always dance even if the approximation is one digit after the comma. I wanted to ask how I can do so as not to make the values vibrate and have a more stable signal. Can it be due to connections? The voltage of 5 volts the son-in-law through an Arduino UNO board.
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cRIO 9066 not booting correctly
Hi
In my project using cRIO 9066 as a master 9049 as a slave both are connected via ethernet hub
Both are working fine.but there is power failure in pannel & power up the power pannel
It wont run my program & also in rt exe mode
During that condition i run the program through labview then click highlight i watch that 2 crio reference is hanging due to that my program unable run ....
After tried sevarel restart both crios
Then its connect.. both crio are fpga programming mode
i have this slove this issue..
During that condition plz help me this problem
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Scripting: assemble Variant defining connector pane
There is Invoke Node Set connector pane. It modifies control (VI ref type). The node works well for setting connector pane of existing VI to control; i.e. connector pane is read from VI (as Variant) and set to control.
Is there any way to assemble this Variant without involving any source VI?
May be there is a way for modifying this Variant?
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Read a .CSV file generated by LabView into Python
Hi,
I'm trying to help with a problem my daughter has...
She has a CSV file generated by LabVIEW from a myRIO oscilloscope and wants to read it into a python script to plot it using matplotlib. The file can be read when you open it in Excel but in python the read command fro mthe CSV module returns an error:
rawdata=open('Ch0_007.csv',"r").read()
File "C:\Users\Username\AppData\Local\Programs\Python\Python37\lib\encodings\cp1252.py", line 23, in decode
return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in position 142: character maps to <undefined>
I've tried changing the encoding to UTF-8 and also to detect the encoding with Chardet but I get the same errors.
Can anyone point to how I can read this CSV using python, please?
Thanks in advance
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arduino visa, error 1 in scan from string, also delayed graph
Hello all,
I'm currently working on a Lab view interface for a Rocket thrust measurement Test stand. We're using an arduino and XBee connection, although for our current tests we've been using a hardwired connection.
The problem is, the serial data input from our test weights is currently being written to graphs at an incredibly delayed rate. As in, I'll take the weight off the sensor and the graph/response will show that fact dozens of seconds later.
We're using VISA in this to receive serial data (the arduino is coded and calibrated to give accurate weight) in the form of pounds vs seconds.
I previously received advice regarding that implied my using of Bytes at Port was part of the problem. My most recent iteration (17, attached) has replaced BaP with Scan from String, but now I am receiving Error 1 at the SfS, saying that 'an input parameter is invalid.' I'm assuming I've not formatted the out/ingoing string correctly, but I'm not sure as to what letters to use for the format box. As said, serially I'm using Arduino via the VISA.
I've attached my older iteration (13) that uses Bytes at Port for comparison.
Are there any other recommended was to decrease the delay? Ideally, we want the graph updated in real time. Also, we're currently unsure as to what unit of measurement the time axis of the graph is using, could you please enlighten me?
Thank you for your help.
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TO AMPLIFY THE VOLTAGE OF PWM SIGNAL
I am working on project of speed control of three phase induction motor using CRIO controller. In i am giving pulse to inverter to trigger IGBT so that inverter can give output to motor. but my pwm signal voltage is only 2.4 v but i need minimum 5v to trigger on the IGBT. so how can i get the required voltage.
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VI starts normally, using an XControl Start button, but when I click the stop button connected to the Loop Condition, nothing happens
I have a very simple app I created to demonstrate a few fundamentals to my students. I created a really basic While loop that runs on a 100ms display. I use 4 Quotient and Remainder functions to divide the iteration count by 36,000 / 600 / 10 and 1 respectively in order to create an hours/minutes/seconds/tenths display. I wanted to show the students how much more elegant you can make an app, simply by adding a Start button, rather than using LabVIEW's Run arrow.
The problem is that, after adding the Start XControl, and placing my loop in a sequence structure and executing that sequence frame via the start button, the loop no longer responds to the Stop button.
I'm sure it's simple, but I'm apparently sleep-deprived. (That and short-term memory issues ever since November 2015 when I suffered a sudden cardiac arrest while running a Thanksgiving day race)
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Help! Charge/Discharge of capacitor
Hi Everyone,
I am in need of assistance with a VI I am creating for a class. I have done as much as I can figure out, or at least what I think should be done. The requirements for the VI are:
A. Theoretical Calculations
a. Calculate and display time constant of the circuitb. Calculate voltage and current up to 10 time constants both for charging and discharging.
B. Design of the VI
a. Display time constant of the circuit.b. Display voltages and currents both for charging and discharging in arrays.c. Display voltages and currents both for charging and discharging in graphs.
The circuit design used for the Vi is:
This instructor provided a "hint" from his VI design:
However, I prefer to use the formula node for most math, and the instructor has no problem with this. However would it be easier for this VI if I actually used math functions like in his example?
I have attached my VI for what I currently have.
I really really appreciate any help!
have a good day 
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