Changing axis in waveform chart

How can I set the x-axis to be something other than time. I want to measure all of my inputs vs. a cycle count. Is there a way to change the axis?
Attachments:
boolean count.vi ‏12 KB

Sorry, I posted the one from yesterday. If I change the name in the property node, will it just change the name? I need it to not be time, and instead be another input, the cycle count. Now that the correct vi is posted, you can see what I'm talking about. Thanks
Attachments:
boolean count.vi ‏66 KB

Similar Messages

Want a constant time axis in waveform chart

hello,
my time axis in waveform chart is changing .how can i keep it constant say 1-100 .the whole point of this is to make waveform chart luk like a CRO.please need help.
thanks in advace
naveen.rabelli

I don't think what you're asking for is possible, due to the nature of the chart - it accepts Y values and inserts the X value automatically. Offhand, I can think of 3 solutions -
The bad one - constantly change the offset by moving it backwords. You will probably have flickering.
The workaround one - Paste a text box over the first number saying 1 and another over the second number saying 100.
The probably most correct one - Use a XY graph. Just have a 1D array of 100 elements and append it to a second 1D array with 1..100. Wire the 2D array into the graph terminal.
Try to take over the world!

Plotting data with multiple y-axis using waveform chart

I am using LabVIEW 7.1 and am simply trying to split my data on one waveform chart using 2 Y axis. One goes from 0-150 and the other from 800-1000. I want them to graph on the same chart, and I have selected 'duplicate scale' when I right click on the chart, as instructed in the labview manual, but both of my data streams are still only connected to one of my axis. I can't get it to recognize that one data stream should go on one axis and the other stream should go on the other axis. Can someone help please?

Right-click in the plot legend one plot. In the context menu select y-axis and after the axis you want for this plot. The scale is changed directly.
There is an image of the context menu attached.
I hope this helps
Greetings
shb
Attachments:
two y-axis.png ‏16 KB

Changing coordinate updates waveform chart?

Hi All, hope everyone is having a wonderful 4th of July.
Alright, so I am new to labview and finding my things around the simple things pretty well, but having never taken any sort of programming interest, Im a bit behind in machine logic, so I figured I would ask here.
EDIT: using labview 2009. Have Vision package
The research I am doing involves analyzing Electron Speckle Pattern Interferometry (ESPI) images and their fringes to observe fracture points/potential weaknesses in different materials and such. I have made a simple VI which allows me to draw a line on the ESPI image and output the light intensities to a waveform chart to make it easier to objectively determine the size of the plastic region (area where fracturing is most likely to occur).
What I would like is to be able to draw or set the coordinates of the line initially, then somehow be able to move it vertically -- using either simply my mouse or a numeric controller -- and have the waveform chart update in real time as i do it.
Any suggestions? Ive attatched my programs, the one called "line.vi" uses numeric input to determine the line coordinates.
Also, since i dont sem to be able to attach bitmaps, ive uploaded a sample image here http://img594.imageshack.us/img594/3566/espiimage.png I dont know why imageshack converted it to a PNG though
thanks all
Solved!
Go to Solution.
Attachments:
line.vi ‏50 KB
light intensity line.vi ‏47 KB

Hi itschad,
did you read the context help of the chart? There it is shown what datatype you need to wire to plot more than one curve on the some chart...
"This made a weird issue where once I select the line, the intensity profile keeps adding itself over and over again onto the end of the chart, so a chart that might initially have been 100 datapoints, just keeps getting longer and longer."
This is how charts work. They keep a history (that you constantly clear). You can set the size of the history buffer. If the default of 1024 points is too much for you you may decrease this to 100 - it's just a right-click away... Otherwise you should use a graph, as a graph only plots the points that are currently wired to it (it doesn't keep a history of previous values).
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome
Attachments:
test horizontal shift.vi ‏48 KB

How to show two different plots with current system time and date on waveform chart

I am using one waveform chart to display the more than one value continiously. The data are comming properly but i am not getting my system (pc) time and date on x axis. It is showing default date and time (i.e.01/01/1904 5:30:45). Please give me suggestions to display the real time and date on x axis of waveform chart.

How does your data look like? Do you graph waveform data types, dynamic data, or plain arrays/clustes? In the case of plain arrays, you need to set x0 to the absolute start time of your data, e.g. with a property node.
I you would attach your code (or an image) we could offer more specific advice. There are too many possibilities.
LabVIEW Champion . Do more with less code and in less time .

Multiple Axis Waveform Chart History?

Hello Everyone,
Recently I have been working on increasing my capabilities with waveform charts. I am plotting 3 signals on 3 seperate axis. I'd like to be able to transfer the plot history from one chart to another via property nodes. The problem is, only 2 of my signals are making it through, and I'm not sure why.
For a little background why my code is structured the way it is, I followed an example from here:
Pausing Charts
Basically I want to be able to zoom in on the chart while the program is running. By hitting pause, the data is transfered to another plot that isn't being updated. Again, only 2 of my signals are making it through, and I'm not sure if there is a property node I'm missing.
Any help would be appreciated, the VI is attached below.
Thanks,
Alex
Attachments:
Chart Test.vi ‏39 KB

For some reason the "Brake Temp" plot's color was screwed up. If you look at the legend it looks like it's black. However, changing the plot's color doesn't seem to have any effect. If you just recreate the "pause" graph by copying the "Waveform Chart" indicator then it will work.
Suggestion: look into the Event Structure.

Size of waveform chart window changes during remapping in SIT

Hi All,
I am using SIT 3.0.3 with LabVIEW 8.2.1. For had been facing a problem where each time I start the host VI the control & indicators would change their ranges. Especially the waveform charts used to change a lot for example the plotting area inside the chart would move a lot to the left making the scale invisible. Which makes it very difficult to understand the signal. Then I would the following KB article which solved a part of the problem.
http://digital.ni.com/public.nsf/allkb/234E19202757CFE8862572AE005559A2
But even after modifying the labview.ini file as mentioned in the KB still the waveform chart changes each time I remap the mappings using Connection manager and the I have to manually make all the adjustments again. Is there a way that I can avoid the automatic readjustment of the indicators and keep size, range shape etc intact.
Thanks and Regards,
Vicku.

Is the chart itself set to autoscale? Right-click on each of the axis and see if autoscaling is checked.
Mike...
Message Edited by mikeporter on 08-25-2007 08:58 AM
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LabVIEW Champion
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Waveform chart time axis is not matching the waveform data

So here an interesting conundrum I hope you might be able to help me with...
My VI has waveform data sent to a chart, though the data is not being plotted against the current time. Rather, it is being plotted starting way back in the reference time (way back in 1903). I don't understand why this is happening. When I build the waveform, I use the "Get Date/Time in Seconds" function outside the while loop and feed that into my "Build Waveform" Function as the t0 value. My dt value is 0.05 (20 Hz) and then I feed in my array of data in the Y input. Any ideas why the chart is plotting this data over 100 years ago? Thanks!
Andrew

Hiii, Ronin
Here is your solution.
By default, waveform charts and graphs display the absolute time at time 0 as 7:00:00 PM, 12/31/1903 on a Windows based system. Property nodes can be used to get the correct absolute time to display on the x-axis of the waveform chart.
First, right click the chart on the front panel and select X Scale >> Formatting. Then set the format to Absolute Time.
Create a property node for the waveform chart by right-clicking on the chart on the block diagram and selecting Create >> Property Node. Expand the property node to display two properties. Select the Format property and the Offset property. The Format property is located under X-Scale >> Format and Precision >> Format, and the Offset property can be found under X-Scale >> Offset and Multiplier >> Offset. Right click on the property node and select Change All to Write.
For the Format property, the context help shows that there are multiple inputs to this property. Wire in a value of 7 to set the format to Time and Date.For the Offset property, first wire the output of the Get Data/Time in Seconds VI to the input of the To Double Precision Float VI. Then wire the output of the To Double Precision Float VI to the Offset property.
In addition, if you know the number of data points plotted to the chart per second, you can set the Multiplier property located under X-Scale >> Offset and Multiplier >> Multiplier. If there are x data points generated per second, wire in a value of 1/x to the Multiplier property. A simple example program "Chart with Timestamp" that demonstrates how to do that is attached.
Thanks,
Nishant
Attachments:
Chart with Timestamp.vi ‏36 KB

Can waveform chart be given focus when modifying y-axis numeric scale

Hello,
I have an application where I have a waveform chart (LV7.0) and a string variable on the same screen. Since, in this application, a user inputs data into the string with a bar code reader, and since that can happen at any time, I constantly give the string control key focus. This is done within a loop. The problem is, I want to be able to double click the y-axis scaling on the chart and modify it at runtime, effectively zooming in or out on the chart. Ideally, during modification of the chart, the chart would have key focus, and I'd set keyf ocus on the string control to be the inverstion of the key focus of the chart... but that doesn't work. Does anyone know how to do what I'm trying to accomplish?
Thanks.

Hi rickford66,
i think you can use an event structure for it. Set the key focus of your control in the timeout case. You can change the timeout depending on the user events. Another solution could be to use the key down event of the VI to read the barcode.
Hope it helps.
Mike

Waveform chart x-axis in time (secs)

Ok here's what I'm trying to achieve (unsuccessfully at the moment). I've got a 2D array of data collected from a sensor. Each column in the array corresponds to one of the sensor's axes. I want to display 3 columns of data on a waveform chart with the magnitude of the data as the Y axis and time as the Z axis.
Here's the tricky bit. I have no timestamp with the data. However, I'm taking the first element of data in each column as being T (time) = 0. The sampling rate of the sensor is 100Hz so => dt = 0.01. So each data element in each column (sample) is separated by 0.01 seconds. Therefore by knowing the number of samples in a column of the array, I can get the end time. E.G. 1000 elements in one column of the array => end time, T = 1000 * 0.01 = 10 seconds.
So in the above example the chart's time axis should go from t = 00:00:00 to t = 00:00:10. However I'm not gettin anything like this in my chart. I did up a quick vi showing what I'm currently doin.
Any tips?
Attachments:
2D waveform chart.vi ‏32 KB

I've re-attached my example vi with a minor adjustment highlighting the problem. Each column of the array now contains 2000 elements which exceeds the deafult chart history buffer length value of 1024. This causes problems with the time display on the chart. I could of course change the chart history buffer length manually by right clicking etc. but would need to do it in real time in my actual vi as I won't know the size of the array until execution.
Is that clearer?
Running the vi now should show you, the time starts at 00:00:09 instead of 00:00:00. I understand why but not how to fix it...

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

Changing the Axis Names in Chart

Hi All,
Do we have an option to change the name of the axis in the chart ? I have 3 bar type charts, instead of the common field names I want the custom names to be displayed. Is it possible, please suggest.
Thanks
Natraj

Hi,
Yes this is possible, if you go to 'Edit View' on your chart. Just under your report title there is a small button, if you hover over it you'll see the label is "Axis titles and labels". It's displayed as a small chart icon with an 'A' in it.
Thanks
Oli @ Innoveer

How do you change the Number of Plots Shown property of a Waveform Chart at runtime?

Is there any possible way to change the Number of Plots Shown property
of a Waveform Chart at runtime? Thy Dynamic Stackplots example is
way to limited.....

There's a couple of ways to do this -
1. Manage the data going into the chart to only be what you want displayed
2. Use property nodes. Specifically, the Plot.Visible node. (LV 7 example attached).
2006 Ultimate LabVIEW G-eek.
Attachments:
MultiPlots.vi ‏48 KB

Waveform chart X-Axis reverses itself when upper limit is edited in Absolute Time - problem may be linked to Timestamp Control?

I've seen this problem for some time now, and it still exists in the Silver toolset Waveform Chart in LV 2012. If the chart is in strip mode, and you edit the upper limit value to a point in the future, the X-Axis will invert (higher values/ later time to the left), to the limit of the Chart History length. This happens whether the chart is active (logging data on a compiled executable) or even when in design mode, though it's more consistent when there's data in the chart. It's not history length related as far as I can tell, as I set the length to 7 days of sampling @ 1-second intervals (605K), and it happens when I try to set the end time to an hour in the future with only a few minutes of data collected - suddenly the right Absolute Time becomes the time my last sample point was collected, while the left Absolute Time becomes nearly 7 days in the future (so neither end point is what I was setting it to).
It's nice that the chart gives the option of editing the limits, but as such, it's important that they work as you would expect them to.
Also - until this is addressed, is there a way to lock it against editing? Until a fix is made, my workaround is to put a transparent button over the range start & end points, and a transparent flat rectangle above all other mid-range points, and pop-up a data entry form with a Timestamp control to allow editing. Unfortunately, this doesn't work as I would expect, as typing "11 AM" in the Timestamp control over a prior value of say "10:05:34.232 AM" ends up becoming "11:05:34.232 AM" instead. ??? Another error - or is this by design? If it's by design, is there an option to make it behave as I would prefer (11 AM = 11:00:00.000 AM), as Excel behaves with timestamps? I can't help but suspect this may be linked to the chart axis issue.
Also - I just built a simplified chart modeled somewhat on my current project, and could not get this to recur. BUT... had the strangest thing happen: My sample data was generated using the Trig functions for Sine and Cosine, and at one point my waveforms distorted on the display, so I'm attaching that here plus the simplified chart project.
Last - my system is LV 2012 on Win7 Pro-x64.
Thanks!
Erik
Attachments:
Chart data distorted.png ‏45 KB
Waveform Chart Flaw.zip ‏17 KB

I am not so sure that this is a bug, and I have not been able to reproduce this behavior that you are describing.
But you can lock it from editing by right-clicking on the graph and go to Properties>>Appearance>>Enabled State --> Disabled
Also, word of advice for the future: You will get more replies from the community with shorter posts and keeping it to one question per post. Summarize what the issue is, and put the detailed documentation and instructions to reproduce in the actual VI.
Huntington W
National Instruments
Applications Engineer
***Don't forget to give Kudos and Accepted as Solution where it is deserved***

How to change output precision of DAQ to waveform chart and to spreadsheet

Refer vi attached, the DAQ connects to a waveform chart to a spreadsheet. I want to change the precision of the DAQ assistant output from 6 decimal places to 2 decimal places, but everywhere i searched on the DAQ assistant i cannot find a precision setting. Did i miss something? What is the elegant way to do this?
Thanks.
Message Edited by sunflower2772 on 09-08-2009 03:57 AM
Solved!
Go to Solution.
Attachments:
all-instrumentasst 5 sep header change.vi ‏220 KB

Hi sunflower,
this seems related to this question...
Why do you want to change the output of the DAQ assistent?
Shouldn't you change the precision of the spreadsheet creation? To do so you simply have to give some parameters to the "to string conversion" functions...
Apart from file saving all other display precision settings are just cosmetics of the indicators!
Message Edited by GerdW on 09-08-2009 11:07 AM
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Changing axis in waveform chart

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