How to Write Waveform graph data to Text File with user option to do so

So, I'm new to labview and am having trouble writing one program in particular. I have a waveform graph that runs for 120 seconds generating a sine curve. I am, however, having a difficult time getting the program to write the x and y coordinates into a text file. I have attached what I have so far.
The first task I was assigned was to write a program that creates a snusoidal curve on the front pannel adding one data point each half second for 120 seconds. The plot should only start when the user presses a start button.
The next part involves giving the user an option to write the generated data to a spreadsheet file called "sine.txt". The file name and location should be hardcoded. The file should contain the x and y coordinates of each data point in columns separated by tabs, also known as delimited.
I have spent several hours tweaking the attached program and I just can't seem to get it to work right. Any suggestions would help at this point.
Sincerely,
A frustrated chemistry student whose research mentor is out of town
Solved!
Go to Solution.
Attachments:
Sinusoidal Curve (saving to excel).vi ‏45 KB

First, you are not creating Excel files. You are creating text files. And it seems that your Write to file is already creating X (time) vs. Y (data curve) that is tab delimited.
Everything else you are doing is just too complicated or a Rube Goldberg.
All you need is the attached.
Attachments:
Sinusoidal_Curve_(saving_to_Text_file).vi ‏69 KB

Similar Messages

How to log waveform chart data in any file at specific interval

i am using labview 7.0. i want to save waveform chart data in the file at specific interval given by user. Please give me solution for that.
falgandha

Open the example finder (Help>>Find Examples) and look at the Write Datalog File example. You can also convert your data to text to save a simple text file. Also, the tutorials in the following links probably cover something similar.
To learn more about LabVIEW, I suggest you try searching this site and google for LabVIEW tutorials. Here, here, here, here and here are a few you can start with and here are some tutorial videos. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide and the LabVIEW user manual (Help>>Search the LabVIEW Bookshelf).
Try to take over the world!

How to write a return in a text file.

Hi, i am trying to write diferent lines into a text file, i write strings ending with \r\n but it doesn't work, how could i write in diferent lines?
Thanks.

PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("myfile.txt")));
out.println("This is the first line");
out.println("This is the second line");
out.flush();
out.close();Jesper

How to write the resultset into a text file

how to write the resultset into a text file

You can use the java.io.* package to write to files.
API: http://java.sun.com/j2se/1.5.0/docs/api/java/io/package-summary.html
Tutorial: http://java.sun.com/docs/books/tutorial/essential/io/index.html

How to write non-XML data to a file using an OSB FTP Routing?

Hi --
Situation ... I need to write non-XML data to a file using FTP. A proxy service retrieves XML and transforms it with XSLT to CSV format, then gives it to a Biz service to file it out, using FTP. Simple.
Problem ... OSB sends the contents of $body to any service it calls. Because $body is a SOAP document, it has to contain XML. So therefore I have to put my CSV data into an XML element, in order to put it into $body; and this inner element then gets written to the file, which I don’t want. But if I don't enclose my CSV content in a tag, I get "Unexpected CDATA encountered" trying to assign it to a variable.
There has to be away around this!
Thanks for your help.
John Taylor

Solved. Steps:
-- Transform the XML to CSV using an XSL transform. Put the CSV data inside enclosing XML elements, and use a Replace action to put the XML element + CSV contents back into *$body*.
-- Define an MFL transform that only knows about the enclosing XML elements. Use a delimiter of "\n" (hard return).
-- Route from the proxy service to a Biz service that has Service Type = Messaging Service and Request Message Type = MFL; specify the MFL transform, which will receive the incoming *$body* variable, strip off the enclosing XML element within it, and pass the CSV contents to the FTP service.
Edited by: DunedainRanger on Nov 29, 2011 9:03 AM

HOW TO WRITE AND READ FROM A TEXT FILE???

How can I read from a text file and then display the contents in a JTextArea??????
Also how can I write the contents of a JTextArea to a text file.
Extra Question::::::: Is it possible to write records to a text file. If you have not idea what I am talking about then ignore it.
Manny thanks,
your help is much appreciated though you don't know it!

Do 3 things.
-- Look through the API at the java.io package.
-- Search previous posts for "read write from text file"
-- Search java.sun.com for information on the java.io package.
That should clear just about everything up. If you have more specific problems, feel free to come back and post them.

How to write list values to a text file?

Hi. Does anyone know how to write values stored in a List to a text file? I have a program that asks the user to enter a name and stores it in a list. The number of names in the list depends on how many times the user wants to enter a name. The problem is that my writeToFile method, which handles writing values to a text file, only writes one name and overwrites any previous names. How could I fix this so that it goes thru the list and writes every value to the file? Any hints would be appreciated!
peace
Chris
import java.util.*;
import java.io.*;
public class StoreNames
String name;
char answer;
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
public void anotherName(List a)throws IOException
System.out.println("Enter another name? (Y or N)");
answer = (char)System.in.read();
System.in.skip(2);
while(answer == 'Y' || answer == 'y')
inputName(a);
System.out.println("Enter another name? (Y or N)");
answer = (char)System.in.read();
System.in.skip(2);
if (answer == 'N' || answer == 'n')
System.out.println("Ok. GoodBye");
writeToFile(a);
//prompts user to input names
public void inputName(List a) throws IOException
System.out.print("Enter a name: ");
name = input.readLine();
a.add(name);
public void writeToFile(List a)throws IOException
PrintWriter output = new PrintWriter(new FileWriter("names.txt"));
output.print(name); //Problem area - handles only one line of input, overwrites previous input
output.close();

System.out is an instance of PrintStream (check the API documents for the System class to see this).
So the easiest way to convert from a "print to screen" class to a "print to file" class is to acquire a PrintStream that prints to a file, and use it exactly the same as you'd have used System.out...
So start with your console code...
        PrintStream out = System.out;
        for(int i = 0; i <10; i++){
            out.println("Number " +i);
        }Then you adapt to file code:
        FileOutputStream fos = new FileOutputStream("temp.txt");
        PrintStream out = new PrintStream(fos);
        for(int i = 0; i <10; i++){
            out.println("Number " +i);
        out.flush();
        out.close();Note that we flush the stream because for reasons of efficiency files aren't necessarily written to disk until you explicitly ask the system to do so (memory is fast, disks are slow, that's why).
Closing the stream releases system resources associated with it.
Actually, that's redundant, because close calls flush automatically, but I left it in for clarity.
Any use ?

How to write & search array data in a file

hi
Can anyone give me an idea about writing an array into a file by placing
each array element in a line and how to search an array element
from that file.
Thanks in advance

Well, you can serialize any object - and of course re-read it.
See http://java.sun.com/j2se/1.5.0/docs/api/java/io/ObjectOutputStream.html for an example.
The easiest way would be to create an encapsulating object, which you then fill with any data you want to serialize. For example:
class mySerializableContainer implements Serializable{
public int[][] myArray;
public String name;
}All you have to do, is to make sure that every attribute you want to serialize also includes the Serializable interface.
So, you don't write one Array after another in your file, but only one object - but make this object as flexible as you need to.

How can I make waveform graph and/or excel file with two different dynamic DBL values?

As the question describes, I have two dbl sources from a load cell and linear actuator (from firgelli). I want to make a load/displacement curve from the force readings from the load cell and the displacement readings from the linear actuator. The load cell outputs an analog signal that can be acquired by a DAQ and the actuator comes in with a board and VI program to control the speed and measure the displacement of the actuator to a sample rate of my choosing. Is there a way that I can make a VI where it continues to collect data and construct the graph I'm looking for?
Solved!
Go to Solution.

A couple points about your application:
1. Synchronization. Since you're ultimate goal is a stress/strain curve, it is vital that your force and displacement data be synchronized appropriately. If your sampling is beyond a few times a second, this is not really possible without some form of hardware synchronization via either a trigger and/or sample clock. Two NI DAQ boards can be synchronized this way easily, but it seems you're using 3rd party hardware for one of these processes. Would need to know more about that board to know what options you have. You could specify what your resolution is in distance, and how fast the article will be moving, to get an idea of how fast to acquire, and how well you'll need to synchronize the data. Another option, since it appears each data stream will be sampled on a hardware-timed sample clock, they will be offset in time, but not skewed during the acquisition. You may be able to identify a feature in the data set common to each and use that to remove the timing offset after the process is completed.
2. Display. To display data during the acquisition process, I usually recommend at least one display that plots vs. time. Much easier to spot irregularities with the acquisition process that way. However, if you'd like to also plot force vs. displacement, you can use an XY Graph to plot parametrically. For Example, in your case you would use the Displacement data as the X coordinates, and the Force data as the Y coordinates.
3. Saving data to file. I would recommend using the Save to Spreadsheet File.vi (File IO pallette) to save your data. If you use a comma as the delimiter, and save the file with a *.csv extension, you will have a file that is easily read into excel. The standard tab-delimited spreadsheet file is also fine, it will just require an extra step to read it into excel to specify to excel what the delimiter is.
4. Batch vs. Real-Time Recording (Data File). If your process is short (< 30 sec) you may be better off acquiring the data, Storing it locally to the VI (Array - usually maintained in a shift register), and then writing the file with a header (acquisition parameters, test article information, data column headers) and the data all at once in batch mode to the file after the process is finished. If, however, it is longer than that you would be better off starting a data file with a header and appending the data to the file as you go, so that if something happens during your test, you at least have data up to that point.
Hope this Helps,
Kurt

Exporting historical data to text file with MAX misses columns of data?

I am using Labview 7.1 with DSC module 7.1 and wants to export data to either excel format or .txt.
I have tried this with the historical data export in MAX, and also programmatically with the "write traces to spreadsheet file.vi" available in the DSC module. All my tags in my tag engine file (*.scf) are defined to log data and events. Both the update tag engine deadband and the update database are set to 0 %.
My exported excel or text file seems reasonalbe except that some columns of data are missing. I dont understand
why data from these tags are not in the exported files since they have the same setup in the (.scf) as other tags which are okay exported?
All defined tags can be seen using the NI hypertrend or MAX. Also the ones that are not correctly exported to file.
Appreciate comments on this.
Best regards,
Ingvald Bardsen

I am using LV and DSC 7.1 with PCI-6251 and max 4.2. In fact, just one column of values does not make sense. In attachment, follows the excel exported file. The last of column called ...V-002 that is the problem. I put probes for checking values but them shows correct. When the file is exported that to show values wrong.
The problem of missing values in column i solved putting 0% in field of deadband.
thank you for your help
Attachments:
qui, 2 de ago de 2007 - 132736.xls ‏21 KB

How to open and read data from text file in PL/SQL

We have a project ,need to open a file containing entries of data
,then process those data records one by one to update the
database.This operation shoulbe be done in the database
enviroment. Is there any hint about the file operation in
PL/SQL? How to open the file and get one record ,maybe one line,
and parse and get the data field ?
thanks
defang

There was also a question on this over at AskTom
(asktom.oracle.com) about a week ago complete with sample code.
The pointer to the sample code is here:
<A HREF="http://asktom.oracle.com/pls/ask/f?
p=4950:8:::::F4950_P8_DISPLAYID:464420312302
TARGET=_blank>http://asktom.oracle.com/pls/ask/f?
p=4950:8:::::F4950_P8_DISPLAYID:464420312302</A>
Admittedly it's about Win95, but the principles should apply.
Yours faithfully, Graham Reeds.
[email protected] | http://omnieng.co.uk/

How to Write log messages in a text file located in another machine

Basically My application is distributed across two or more tomcat servers running in multiple machines.And I get a log4j logs in the respective machines.
But I want a consolidated log message in a single machine.
How do i get that done??
Any samples?? Any clues??
Any specific technoliges??

Create an RMI application (for example) that writes the log, and let all logging calls call that remote application.
Something like that is the only feasible way that doesn't require you to have a drive on the remote machine mapped to the local one (which causes its own problems as you could have multiple simultaneous write attempts...).

How to export waveform data into text file

Hi..
I am trying to export my waveform graph data into write spreadsheet file. When running the proram, I am getting graph values (values in a matrix) when checking with the probe. But once I save it to a text file, the values recorded are just zeros. I have attached the text file along with this. Could anyone please tell me why the graph data is not recorded in the spreadsheet? I have extracted the Y component of the graph and then wired it to the write to spreadsheet function. It seems like the labview is getting the data.. but now the problem is how to get the data out of labview?

Please find the attched image of the whole program. I tried running the program after removing the array to matrix but still I am not able to export the graph values to spreadsheet. The program as a whole is working as I am able to display the oscilloscope graph into the waveform graph but I am not able to export the values. When I tried using probes, I am getting differnet matrix values till the end of the connection given to 'write to spreadsheet' but not able to export the values. The second image shows the write to spreadsheet file inside the while loop as i thought it will reduce the memory.. but it is still not working...
Attachments:
Scanner complete program.jpg ‏713 KB
full scanner program 2.jpg ‏664 KB

How to write data to text file using external tables

can anybody tell how to write data to text file using external tables concept?

Hi,
Using external table u can load the data in your local table in database,
then using your local db table and UTL_FILE pacakge u can wrrite data to text file
external table
~~~~~~~~~~~
http://download-east.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_7002.htm#i2153251
UTL_FILE
~~~~~~~~~
http://download-east.oracle.com/docs/cd/B19306_01/appdev.102/b14258/u_file.htm#sthref14093
Message was edited by:
Nicloei W
Message was edited by:
Nicloei W

How to Add points on graph from a text File ?

Hello and Good Morning to all,
I have a text file with my data and i read them by using the Read From Spreadsheet File VI,i enter the path where my file is saved,read all rows delete the first row because i don't need it and my problem is that in the text folder i have specified date and time which i want to be my X axis in my Graph and Y axis to be the Vout that means i have to use a XY Graph ,below you can see my data:
Date        time              Vout
3-9-2012 7:45:37            2,35
3-9-2012 7:45:39            2,75
3-9-2012 7:45:41            3,15
3-9-2012 7:45:43            3,50
1) Is the text file format compatible with the input of the graph command?
I do not find a LabVIEW function which convert the “date” from the text file (example:3/09/2012 07:45:37) into a compatible format for X axis for the graph.
(Conversion from string format => into a “date and time” format)
Can someone please provide a code solution for this problem?

Hi gstathatos,
                         See all the threads given below:-
                         http://forums.ni.com/t5/LabVIEW/Add-points-on-XY-graph-with-time-step-not-constant/td-p/1507066
                         http://forums.ni.com/t5/LabVIEW/Add-points-on-graph-from-a-text-File-Date-and-time-include-in/td-p/1...
                         http://forums.ni.com/t5/LabVIEW/read-double-waveform-text-file-and-and-plot-graph-in-labview/td-p/10...
Thanks as kudos only

How to Write Waveform graph data to Text File with user option to do so

Similar Messages

Maybe you are looking for