Converting data in waveform graph to an ASCII file

We are using a Labview program to acquire rapid voltage data, however due to specifications on the board we are employing a voltage divider factor that can be changed in the program, as well as sensing the polarity and correcting it so that the voltage is always positive. This data is saved in raw form to a bin file. To view this data, we have another program that has inputs for the scan rate and voltage divider factor, and then it reads the raw binary file and generates voltage vs. time data directly into a waveform graph. No one here actually wrote this entire program, it is my understanding that NI originally helped to develop the program and no one in my group fully understands the intricacies.
What we would like to do is obtain data in 2-column ASCII format from the waveform graph directly (voltage vs. time) in some way. Is this possible, and if so how can it be done? The program is currently run off of Labview 4.1, however we also have Labview 7.0 on another computer and can copy the program and bin files if necessary.
Any help is greatly appreciated.

I'm having some trouble because the data is not technically in a waveform (brownish-red colored wire). The program builds a waveform *graph* (cluster data with pink wire) using the bundle function, where the top input is a dbl x0 that is generated from (1/scan rate) multiplied by the first scan number. The middle input is delta(t), which is just (1/scan rate), and the bottom input is a 2D array of two columns of voltage data, one is voltage and the second is a voltage from another channel that I don't need, and I can't figure out how the 2D array is generated because it looks like it should only be 1D (it suddenly becomes 2D after leaving a for loop). This creates a waveform graph with time vs. the 2 sets of voltage data.
So you'd think you could just build a waveform with the same data, but the "build waveform" function wants a t0 with a timestamp format and a 1D array for the 'Y' input, and I also can't just convert the cluster data for the waveform graph to an array using the 'cluster to array' function as it gives me a data mismatch.
Does anyone know how to remove the first column or row of a 2D array and create a 1D array? Also, how can I input a timestamped t0 if it needs to be on the order of <1 ms, since milliseconds are crucial here? Is there any way to make a waveform with a decimal t0 instead of this ridiculous timestamp?
Thanks again for any help.
Message Edited by chemengr on 06-19-2006 09:23 AM

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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?
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A couple points about your application:
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Hi there,
I managed to save data from waveform graph into excel file and saving the plot into excel but individually. I'm aiming to save both the data and the plot in an excel file. May I know how do I do it? I've tried using the Write to Measurement File vi and also the invoke node of the waveform chart but it's still not giving me what I've wanted.
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No, GerdW, it doesn't work
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Hellow!
I have a waveform graph which has the experiment signal, so how can i do to save the X,Y data in a file?
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Hii,
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Display Data on waveform chart or XY graph over a long period of time

Display Data on waveform chart or XY graph over a long period of time
Can anyone help?
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Real-Time Graph Display.vi ‏170 KB
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Hi,
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I record data from 6 channels using DAQmx with simulated channels and write to measurement file. Then using read from measurement file, and waveform graph, I am trying to graph the data that has been recorded. I am only getting a small amount graphed. The same graph appears whether I have let the measure and record program run for 1 minute or for ten minutes. It also displays a time at the end of the graph that is in the future. What am I doing wrong? Please help.
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I am attaching the two VIs I have been trying to use. I started with examples from NI and didn't go far from that. Any assistance would be appreciated.
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Hi,
First I want to say thank you in advanced!! Let me describe the situation a little bit. My front panel VI (see attachment) has a tab control and on each tab window I have an intensity chart with a free-drag cursor. Below the tab control window I am trying to display either the row or the column of data where the cursor is located, I can do this for each intensity chart individually. I am trying to clean the block diagram up a little bit and instead of using 4 Waveform Graphs, I want to use only one, can the data that is displayed in the wave form graph is associated with which page is active on the Tab Control. Can this be done? And how can I do it?
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~Daniel DeWitte
Solved!
Go to Solution.
Attachments:
Changing Waveform graph data.JPG ‏123 KB

Simply wire the tab terminal to a case structure that switches the data going to the graph terminal
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LabVIEW Champion . Do more with less code and in less time .

How does waveform graph downsamples the data before it is plotted

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I'm interested in how does waveform graph downsamples the data before it is plotted and what algorithm is used for this purpose? My goal is to plot 30 plots that have 1M samples each and I would like to downsample them before plotting onto a graph. I tried several VIs/algorithms for resampling and none of them gave the same result as seen by waveform graph (when all the samples are plotted).
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Solved!
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Attachments:
WFGDownsampling.vi ‏19 KB

Hi andrej,
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Append data to a waveform graph

I am using the Acquire N - Multi-Digital Trig to acquire a series of data. I wish to store the data acquired, by saving them into a file (Export Waveforms To Spreadsheet File) however, the waveform graph data are not appended. I have tried to see the example provided for appending data to a waveform graph (example.zip) on this webpage but I wasn't able to apply the principle to my application. (I have even tried the Append Waveforms.vi function but I cannot connect it to the waveform graph data).
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There is an Append Waveforms.vi that you can use for this. It's located in the Functions>>Waveform>>Waveform Operations palette. That will append two waveforms, which is different from just an array. If you only want to append arrays, you can use the Build Array function to concatenate two arrays.
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Is there a way to change the time of a saved data to be as the same as the time-axis of the waveform graph?

Hi,
I've a problem while saving the waveform to a spreadsheet.
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Attachments:
Modification of 2 CH waveforms (Multiply and Sum).vi ‏63 KB
Modification of 2 CH waveforms (Multiply and Sum) Front Panel.JPG ‏220 KB
Modification of 2 CH waveforms (Multiply and Sum) BD.JPG ‏92 KB

I've saved it as text file which could be read if I open it with excel spreadsheet.
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waveform vaule.txt ‏433 KB

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I created an Xcontrol for a waveform graph. The datatype (under Data 1.ctl) is a WaveformGraph reference type.
When I wire a Waveform graph reference to the Xcontrol (as an indicator), there is a wire conflict.
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Attachments:
GraphDisplay XControl.7z ‏1717 KB
Tester.vi ‏15 KB

It looks like the XControl data is a waveform reference (strict). I can't open the XControl though, because I don't have a 7z compiler, but the problem is probably that the refnum will only take in a reference to an exact waveform graph because it's strict.
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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.
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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.
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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.
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Attachments:
Sinusoidal_Curve_(saving_to_Text_file).vi ‏69 KB

Converting data in waveform graph to an ASCII file

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