Programmatically Extend a Waveform Chart

Could anyone kindly tell me what property node I can use to programmatically extend a Waveform Chart on my Front Panel.
For instance, if a Boolen button is in the True Case, the Waveform will be short, but when in the False Case, the Waveform will be automatically elongated/extended beyond the initial length.
Attached is the screenshot of what are trying to describe.
Thanks in advance.
Solved!
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Attachments:
Waveform.PNG ‏11 KB

RavensFan, thanks for your response. It actually worked for me. Although, you answered my question already, but just allow me to ask one more thing under this thread. If I want a flat line known as a "baseline" a numerically controlled/adjusted value to appear on the same Waveform Chart that my incoming signal(s) is/are plotting, how do I imposed or put that "baseline" on the same waveform chart? The "baseline" is only acting the purpose for comparison or threshold?
I would appreciate if you could just help with suggestion.
Thanks

Similar Messages

How do i set the time frame of a waveform chart programmatically to be a 30 sec window or a 24 hour window

i'm using LV7.0 and what i need to do is to be able to set the time frame or range of a waveform chart programmatically before i start taking and plotting data. sometimes this window needs to be 30s wide and sometimes it needs to be 24 hrs wide. (in the first reference, i need the chart to fill up with 30s of historical data then the whole chart scrolls with each new data point). the data acquisition records data at a rate of once per second. i've tried to use the chart properties of XScale.offset, XScale.Range.Minimum and XScale.Range.Maximum but no matter what i do the time-stamp on the x-axis is always "00:00:00 PM" and "MM/DD/YYYY" even though values are seen being plotted on the right side of the chart as expected.
Attachments:
BX0265 ShelfLife DAQmx.vi ‏120 KB

Okay, there seems to be some confusion here -- the X axis values are of type double, but they can be represented in the HH:MMS MMD:YYYY format if you want in which case it interprets the floating point as the number of seconds since 6pm Dec 31, 1903.
You can programmatically set this value using the XScale.Minimum and XScale.Maximum properties, but note that if you wire a waveform to the chart after setting these values the t0 parameter will override what you set using the property node for XScale.Minimum. If instead you leave the t0 parameter empty you can use the XScale.Offset property and wire the same value in that you wire to XScale.Minimum. Changing the amount you add to XScale.Minmum to obtain what you wire into XScale.Maximum will determine the time window size.
Doug M
Applications Engineer
National Instruments
For those unfamiliar with NBC's The Office, my icon is NOT a picture of me

How Clear a WaveForm Chart Programmatically?

Hi LabView Masters!
Can I Clear a WaveForm Chart Programmatically?
I know that I can clear the chart clicking with the mouse, but I need to
clear it when a particular variable is high. (Programmatically)
I have been testing the Attribute Node but I didn't got it.
Thanks in advance for your help!.
Francisco Javier Fernandez Luna
Ingeniero Tec. Industrial en Electronica.
Tel: 619 81 98 31
E-mail:[email protected]
ó [email protected]
"Let's make things better" (PHILIPS)

try to use property node of the chart and connect an empty array to
"history data" field
Paco Luna a écrit dans l'article
<01beae87$7fe22e60$[email protected]>...
> Hi LabView Masters!
>
> Can I Clear a WaveForm Chart Programmatically?
> I know that I can clear the chart clicking with the mouse, but I need to
> clear it when a particular variable is high. (Programmatically)
>
> I have been testing the Attribute Node but I didn't got it.
>
> Thanks in advance for your help!.
> --
> Francisco Javier Fernandez Luna
> Ingeniero Tec. Industrial en Electronica.
> Tel: 619 81 98 31
> E-mail:[email protected]
> ó [email protected]
>
> "Let's make things better" (PHILIPS)
>

Auto update waveform chart error

Hi all!
I have come across the problem when working on my VI. As you can see from the VI that I have attached, there is a waveform graph on the front panel for data acquisition. The value shown right now is from time, 00:00:00 to 00:05:00 (0-5minutes).
The problem that I am faced right now is, everytime when I hit the run button, LABVIEW seems to automatically change my time value to some sort of generic time. What I want to accomplish here is that, I want to acquire data on the waveform graph from time 0 to 5 minutes. Also, I would like to specify the increments myself. For example on the time scale (x-axis) from 0-5 minuntes, I would like a 30 seconds interval between them. How do I actually accomplish it?
I have tried absolute time format and changing my waveform chart to sweep chart.
Thanks for any help!
Jlam
Attachments:
PDaq- Modified_07-08-2010.vi ‏61 KB

The problem here is that Waveform Charts and Graphs always assume a constant delta time between data points. If you are absolutely certain the data points are guaranteed to be sampled at consistent intervals, the Waveform Chart or Graph is a good fit for the data.
On the other hand, if data points are sampled at arbitrary time intervals, it will be necessary to use the XY graph, where different timestamps for each data sample determine the t-axis (time, horizontal axis).
The deal here is that your horizontal axis is N, Sample Number, not t, sample time. Your samples start at 0, and increment 1, 2, 3... Therefore, if you are taking 120S/sec, it will appear two minutes - 00:02:00 (HH:MMS) - have elapsed in the first second! One way to convert Sample Number to Time is by mulitplying that scale by the factor 1/120. To add a multiplier (or offset) to your scale, go to the properties of the Chart. Likewise, you can use a property node to programmatically set scaling factors on the scale.
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Only first plot of waveform chart has run-time menu

Hello again all you helpful forum-goers!
My multi-plot waveform chart is working decently well, but now for some reason only the first plot in the plot legend displays a run-time customization menu when I click on it while the VI is running (allowing me to select the plot color, etc.). All the other plots do nothing when I click on them. I do not have any mouse-down events or filter events of any kind in my VI. I programmatically set the number of plots and the size of the plot legend, along with each plot's name, y index, and color. Any ideas as to what might be going on?
Thanks a bunch as always!
-Joe
Solved!
Go to Solution.

Okay, hopefully this will help get some more thoughts / answers flowing. I've copied my strip chart from my actual VI into a test VI, and it still exhibits the problem. On the other hand, I have created a new strip chart from scratch, and it works fine. I have attached both VIs here for you to see. My guess is that some property of the first chart is set incorrectly or something, but I cannot figure out which one (and there are so many!).
Any assistance you can give would be appreciated. The challenge is to get the chart in the first VI working (plots other than the first responding to a mouse click to change their color or other attributes), via changing some attribute of the chart (and being able to tell me which one you changed!).
Thank you again for anyone who can look into this.
-Joe
Attachments:
Test StripChart color selection not working.vi ‏17 KB
Test StripChart color selection working.vi ‏12 KB

Legend for multiple waveform chart

I have a Waveform Chart (and legend) with multiple waveforms. I can control the visibility of a given waveform on the chart programmatically using the "ActPlot" and "Plot.Visible?" properties.
Is it possible to programmatically make the legend only contain the plot names that are visible at any given time?
Cheers,
Dan
Dan
CLD

Hello DanB,
Following along the lines of what smercurio_fc suggested, you can use the Legend>Number Of Rows property (LegNumRows) to change the number of rows of your legend to the number of plots you are viewing, and then use the Plot>Plot Name property (Plot.Name) to edit the names of the plots yourself. I cannot see a property to extract these names dynamically, so this is probably your best bet.
I hope this helps, otherwise please do let us know if there is anything further,
Kind Regards,
Michael S.
Applications Engineer
NI UK & Ireland

Problems with waveform chart

Hi guys,
here I am again with another issue... I just need your help to a small issue, the attached VI is my project...the problem i have is that my waveform chart only shows 0.065 seconds of data, i needed it to show the total time of the test...if possible, coordinated with the time selected by the user in "time to test"...
Is it possible?
Can anyone please help me?
Best regards,
Jimmy
Attachments:
Ensaio de Rugosidade_01.vi ‏221 KB

Hi,
Right click your chart and select properties. In properties set the X axis scale minimum and maximum values as per your requirements. Select autoscale if you want it to be automatic. To set the X axis scale programmatically, select the property node X-axis->Range and wire the limits accordingly (in your case, you can wire it to the "time to test".
Regards,
Nitz
(Give Kudos to Good Answers, Mark it as a Solution if your problem is Solved)

How can i display Waveform chart in a subpanel using Vi templates.

Hi All
I am new to Labview hence need some help. I am trying to develop an application which reads some data from a Wireless Sensor Network (WSN). The WSN consists of base station connected to the USB port which recieves data from other sensor nodes. The data comes in a certain format. Node name, temperature reading, humidity reading etc. I want to read the data from the serial port and based on the Node name, i want to display the information for each node in s separate window or subpanel etc. So if a new node is detected then a new window is created for that node. Since all the nodes have the same sensors on board i only need a one template. I can read the data using the serial port, parse the data to detect which node it is and also what the sensor readings are. I have created a template VI for the sensor node. I am having problems in displaying the template VIs in a subpanel. I can succesfully display a Waveform graph in the subpanel but i am having problems in displaying a waveform chart in the subpanel. I can see the actual waveform chart in the subpanel, but i cannot see the plot. Would be greatful if someone could point out what i am doing wrong here.
Many Thanks
Raza
Solved!
Go to Solution.
Attachments:
template_graph.vi ‏16 KB
graph_template.vit ‏11 KB

Hi All
I think i have solved the problem. It seems like i was running the Vi in a loop. I have taken the Run Vi outside the while lopp and this works fine. Also i need to close the reference at the end.
Raza

How can i print out the waveform chart?

hello everybody,
how can i print out the "waveform chart". can i do it just push the button. ( example; stop button is stop the program etc..)
i checked the NI examples but i can't understand. i'm new to the Labview.
pls help me.
i added the my program
look forward your reply
regards from turkey...
Message Edited by hknmkt on 05-29-2008 04:15 AM
Attachments:
29.05.2008_11.vi ‏37 KB

hi jim,
i tried the program but it's not running. When i run the program, it's print out without run the program
i added the printed file.
look forward your reply
hakan
Attachments:
error8.JPG ‏8 KB

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?
I am acquiring data from an Ni DAQ card with the following parameters - sample rate = 12800, number of samples = 4096. I want to extract order information so as to track changes in the amplitudes of certain frequency harmonics. So I use the sound and vibration toolkit to extract this information as shown in the attached Vi. I will like to plot the resulting amplitudes against real-time starting at the time the Vi was run. I really want the display to show these changes over long periods (eg. days, months and even years).
Problem.
I have tried to plot the Y component of the resulting magnitude for a given order on a waveform chart. My choice of the waveform chart is because I also want to display alarm limits (using the mask and limit vi) (I can't have these lines displayed on an XY graph plot). I tried adjusting the scale offset using the property node and setting the offset to current time. However, the display on the X-axis can only show a span of 2 minutes as will be seen when you run the attached vi. I want the time display on the x-axis to be over a period of days, months and even years. Is there a way to set the maximum scale on the x-axis to be say a year or so in future.
I really want the display to be like the one in in the second attachment.
Attached is a sample VI created using an Ni USB 9234 DAQ card. Any card will do but I am only getting the signal from one channel for this example
I will appreciate any help that can be given to me.
Thanks
Attachments:
Real-Time Graph Display.vi ‏170 KB
Sampe screen1.doc ‏37 KB

Long term testing can be tricky- and we'l get into that later. Lets start with the basics that you have wrong.
The vi as you have constructed it has only one memory element, the chart history length (default is 1024.)
You can change the number of points the Chart will remember by Right-clicking the chart an select Chart History Length from the menu.
But for a long term test - and one where you want to REMEMBER the first value you need a memeory element that is independant of the application. Your PC WILL loose power or need to be rebooted eventually. Heck it might even need to be replaced! you really need to store your data in a file. Preferablly in a file that is backed-up on a regular basis so you don't lose every point of data if the PC dies. It realy hurts when you have to restart a 2yr test because you've lost the 18months of data you collected.
For an application like this I would seperate my "collection" and "Evaluation" operations.
Have one vi that takes the reading and writes it to a file at a configurable rate You may want 1reading per minute for seveal days then 1 per hour for a few weeks- then maybe only once or twice a week for the next couple of years since you are looking for LONG TERM stability. having too much data to evaluate can take a lot of digging to find the few things that interest you (but always take more that you think you need)
Have another utility that COPIES the files, reads them and displays the data you are interested in that day. The data you want to look at won't change over time HOWEVER, you WILL want to analize it in different ways depending on what the data trends look like. Having seperate routines for collection and display allows you to update the display style and analisys without even stopping the collection vi (much less editing the vi)
Jeff

How can I display more than 1 loop iteraction in a waveform chart?

Using DAQmx, I am inputting a signal at a rate of 10k with 1k samples inside a while loop. I want the first 3 seconds of data to display on a waveform chart without having to change the rate or number of samples. Is there a way to stop the waveform chart from clearing after every loop iteration so that I can display more than 0.1sec of data? Thank you for any help you can provide!

The default history length of a chart is 1024. To make it longer is a right click option.

How do I add a time stamp to the moving "Major Grid Lines" of a Waveform Chart?

Hello
I am using LV 8.5.1
I am using a Waveform Chart and I have turned on the "Major Grid LInes" using the properties tab of my waveform chart. (properties-->scale->grid lines)
When the code executes, I want to attach a time stamp to each moving yellow grid line.
So as the grid lines move from right to left, there is an associated time stamp for each.
Can someone help!
thanks
J
Solved!
Go to Solution.
Attachments:
how do I add time to the yellow grid lines.vi ‏16 KB

hova2010,
If you right click on your graph and go to X Scale >> Style >> and then choose one of the 3 styles on the far left you shoul see timestamps for those grid lines.
Ben Sisney
FlexRIO V&V Engineer
National Instruments

Combining 2 readings into a waveform chart/graph displaying continuous readings of data from different sources

Hi,
In the file
(Serial Read and Write to .tdms & Compare on Graph – test.vi) I am trying
to integrate the following two waveforms into a single waveform: Realtime
reading and Waveform chart (open vi to see). Both of them display speed vs time
but from different outputs. One comes from an excel file (Teraterm – Results.xlsx
– sheet 4, (column 3:row 4) to (column 3:row 1878)) and the other comes from
the Serial input which is in Hex format and is split to get the various readings
of speed, voltage etc. I have already wired speed to a variety of waveform
outputs, but all result in broken wires.
The readings are taken in by the program
and but I am unable to wire the two readings together into one graph.
Please do let me know as to how can I make this work.
Thanks in Advance.
Best Regards,
Akhil
Kumar Meesala (Mr.)
Year
4 | Undergrad | Mechanical Engineering
National
University of Singapore
Email:
[email protected]
Mobile:
(+65) 9326 7069
Solved!
Go to Solution.
Attachments:
Serial Read and Write to .tdms & Compare on Graph - test.vi ‏58 KB
Teraterm - Results.xlsx ‏593 KB

Dear GerdW,
I'm sorry again about the misspelling your nick.
I tried connecting a waveform chart to the two terminals (speed from the DAQ and speed from the excel file) but I was unable to get the connection right. I understand that charts are used for readings which are equally spaced out, whereas XY graphs are used when the readings are not be spaced out uniformly. But I am unable to wire the connections correctly.
Actually the DAQ device continuously sends out data through the serial port. So I would not run out of data . Are you referring to the data coming from the DAQ device or the excel file? I actually have not thought of what would happen when the excel file would run out of values I am just hoping for the software to run till then for now
I have cleared up the wires as well Thanks for your help.
Best Regards,
Akhil Kumar Meesala (Mr.)
Year 4 | Undergrad | Mechanical Engineering
National University
of Singapore
Email: [email protected]
Mobile: (+65) 9326 7069
Attachments:
Get Excel Values.vi ‏25 KB
read_excel_values.llb ‏201 KB
Serial Read and Write to .tdms & Compare on Graph - test.vi ‏79 KB

How can I change the color of plot in a waveform chart and graph?

There are 4 plots in a waveform chart, from plot0 to plot3, and I want to chang the color of plots dynamicly up to my needs when the VI is running.
For example, as show in the picture, i want to set the plot0 as RED, and plot1 is BLUE, plot2 is YELLOW, plot3 is GRAY.
If there is only one plot, i can change it's color, however when there are more than one plot, it fail.
How can I do it?
Thanks
Attachments:
waveform.JPG ‏61 KB

Hello MilkyStone,
first you have to set the active plot, then change its color (or other properties). All that is done using property nodes.
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

How to take the print out of the entire data from the waveform chart

i am using cont acq to spreadsheet file.vi to acquire data from a number of channels. this vi also plots the acquired data on the waveform chart. i want to take the print out of the entire data. how can i do it ?
also how can i take print out of the data between given interval??
please reply me
thank you

There are a number of different ways of achieving your goal. Depending on which version of LabVIEW you have and which development environment, the Report Generation Toolkit is a very powerful tool. Attached is an example that prints the acquired data without the use of additional toolkits.
Jonathan Hildyard
Applications Engineer
National Instruments
Attachments:
DAQ_with_Print.llb ‏115 KB

Programmatically Extend a Waveform Chart

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