About waveform chart

hello ,
actually i want to ask that how can i change the data format of the
Waveform graph, by defult it shows as DBL but i want to change it to
cluster icon or SGL etc..
if any one cant understand my point plz look at the attach image i want to change it like that.
thanx
Attachments:
waveform graph.JPG ‏57 KB

The waveform graph terminal will automatically adapt to whatever datatype you wire to it. Just wire waveform data to it and it will change apperance and functionality accordingly.
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Similar Messages

Question about waveform chart time scale

Hello,
I have question regarding to time scale on my chart, I want it to show the actual measured time, for example from 0-30 seconds, but instead my minimum value is 302654789854 . Please help me to fix it.
Regards ,
Stella Deheryan

You can modify the way the time is displayed on the axis by right clicking the chart and selecting properties. On the display format tab, select relative time. This should show the X-axis scale as HH:MM. Or pick any other type of formatting you want.
Best Regards
Michiel
Applications Engineer
NI Belgium
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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

Using waveform chart to collect data

Hello,
I am a new user to labview, however I have been using it for a while now.
I have a simple problem.
My model runs a drive cycle for 1400 secs.
I want to record data for a sample rate of 1 sec.
However, When I try to run the model and export it to excel it shows data for a sample rate of 0.1 seconds. How can I change that?
Also, what can be the maximum buffer size of the waveform chart?

Hey govindgoal,
The max buffer size is pretty massive so don't worry about that. I would post your code or at least the part which is recording the data for people to help debug. It would seem however that you have some timing issues with your application.
Regards
Andy
"To 'G' and not to 'C', this is not a question!"

How to set maximum number of data points displayed on waveform chart?

I have a waveform chart set to x-autoscale, but after about 1000 data points, it begins to scroll again. How can I display all of the data points being collected, say 2000 points?

Right click on the chart and select Chart History Length. Enter the value that you need. The maximum is 2147483647 points.

Time stamp on Waveform Charts

I'm making an application where I sample data every 5 seconds. I use the Time Delay VI to obtain the sampling interval, and then set the chart options using chart properties/format and precision/relative time. The chart is adding a point every 5 secs as it should, scale looks ok. However, the time scale on the graph is incrementing only one second at the time (although actual time elapsed is 5 secs). The log file gives the time stamps just as it should. Is there a way to make the waveform chart give the real time (other than the obvious solution of sampling 1 pt/sec)?

I'm just directly passing scalar values to the chart. The total acquisition time is about an hour, and the idea is to display data as they vary with time.

Trouble using a mask on a waveform chart

I have created a waveform chart that plots the
temperature readings from my thermocouple. It is making continuous
readings, and I can take the data from the text file I created and
graph it in excel and everything is fine. However, my temperature
readings have to follow a standard temperature vs. time curve with a
limit of 10% error. Since I need to me able to compare the live data to the standard curve, I created a mask by inputing the data points for
the upper and lower limits and hooked it up, and now my chart will not
work. When I checked the data on the text file it only makes 3
readings and then starts over (i.e. gives a reading at 0 sec, 1 sec,
2sec, then starts over). I have tried using N readings instead of
continuous and nothing seems to work. Can anyone help?
Thanks!

Carla,
Attached is the program I made. I am using Labview 8.2 with a NI cDAQ-9172 chassis, and a NI 9211 input module. By inputing data points, I meant that I took the required data from the temperature vs. time curve I have to follow and placed them in the table that the masking.vi allows and set dx=1.
Basically, what I am expecting to happen is that I will have a chart with streaming data of what the current temperature inside the oven is, along with the upper and lower limits of what the temperature can actually be. This way, I will know whether I need to heat the oven up more or cool it off (the testing will last 4 hours).
I attached an excel file of the actual curve to give you a better idea of what I am talking about.
Thank you for the help.
Attachments:
Tempcurve1.xlsx ‏16 KB
Burner(testing)1.vi ‏393 KB

Waveform chart data to file

dear sir,
iam getting eight different plots on waveform chart with system date and time. Now i want to store this eight values with system date and time in excel file as per specified time interval. it shoould be online because i don't want to stop my vi to save that data in file. Is it possible? If yes please help me.
thanking you
falgandha

Falgandha,
this can be done with ActiveX or just saving the data as spreadsheet file and then importing it to Excel.
If you like to know more about Excel and ActiveX, you should take a look into the ActiveX-examples of LabVIEW.
Saving data as spreadsheet file is available as examples as well, but maybe it is sufficient for you to use the "Write To Spreadsheet File.vi" from the file IO palette.
hope this helps,
Norbert B.
CEO: What exactly is stopping us from doing this?
Expert: Geometry
Marketing Manager: Just ignore it.

Labview absolute time waveform chart to excel

Hi everyone, I have a bit confusing on absolute time waveform chart. My problem is when I want to export to excel, the data duplicate nearly 30 times for each second. My project is about collect temperature from serial port and plot it in waveform chart, and I want to view history data in excel.
Anyone can help to solve my question? I attached my vi here..
Thank you so much..
Attachments:
NEW FINAL1.vi ‏96 KB
snap.PNG ‏11 KB

You are getting such a large number of readings because your VI has no timing control in it, if you simply add in a delay somewhere of maybe migrate to an event structure with a timeout then you can control the number of readings that are taken per second.

Waveform Chart Update With Relative Time

Hey,
I have a question about how a waveform chart updates. I am running a test in the pictures attached it is only for 4 minutes and I read in a data value every 90 seconds. I was wondering why the waveform chart doesn't look like chart 2 (photoshop what I want) instead it looks like chart 1.
I pass to the waveform chart a double every 90 seconds or so. How can I make the chart behave like picture 2? Where it connects the data points with the time each data value is sent to the chart.
Attachments:
Chart1.png ‏26 KB
Chart2.png ‏10 KB

Actually if you look carefully at chart 1 it appears that it is connecting the dots. But the time scale is messed up. Can you post some example code?
Mike...
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Waveform chart-drop in pressure

Hi,
From couple of days I am working on a code to read pressure drop in continuosly running waveform chart. I checked lot of examples and in the whole forum but I am unable to find anything close to what I need. I need to read two points from the waveform chart and difference between them. Please help me.
Thank you,
VG

Well, the VI you attached really doesn't help at all, it pretty much just shows you know how to find an Express VI from the palettes.
However, I've fixed my signature so it points directly to two tutorials (Sorry, didn't realize that I messed it up so bad). You really need to go through both, but work the first one first. Unit 2, Lesson 4 deals with arrays. But, please start from the beginning of the tutorial, because it all should help you.
Trust me, working through these first will make you much less dependent on the slow process of waiting on others in the forums to step you through your project and actually speed up the whole process, even though it takes precious time to go through them.
Cameron
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Waveform chart gaps

Hi,
If completed my application for data acquisition, onlyi'mnot that happywithmy waveform chart... It shows gaps, time to time? And i don't know why?
Here is an example:
Does anyone has a solution for this?
Regards,
Thijs

The only time I've seen gaps in graphs or charts, is when you try to graph the value "NaN" (not a number). This usually comes about by doing some math that has a result that can't be represented. Dividing by zero is a common way of making a value NaN. You'll need to do some debugging to figure out why your value became NaN and probably use the Not a Number check (under the comparision palette) to catch when this happens.
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Horizontal scrollbar of waveform chart in tab page resets to end when tab page switched

I've got a VI in LV 2012 with a chart in one of two pages of a tab control. Whether compiled to an executable or not, when the waveform chart contains data that is no longer being updated and the x-axis range doesn't show the last point of data, the horizontal scroll bar auto-adjusts to show that last point if you switch pages (back to the chart) on the tab control. I've tried turning off Autoscaling but that doesn't stop the effect.
Additional issues:
On some of these attempts at reproducing this, the X-Axis will even change scaling, zooming in on the data.
When data is pushed left by this bug to allow displaying the furthest data point, if the leftmost area of the chart was blank before the data was pushed left, the data pushed left into the formerly blank area will not be displayed. This happened only when the X-Axis was manually autoscaled prior to pushing the data off the right edge of the chart, and only if the x-axis scale was not changed. If the tab pages are again switched at this point away and back to the chart, the data re-appears.
The chart is a stacked plot if that makes a difference, Also, the tab control is not linked to any event handlers.
Also, the scrollbar works fine if you scroll such that the rightmost data points are on the chart along with blank area to the right, whether there is more data off the left edge of the chart or not.
Last, the Y-Axis of each stacked plot is unaffected by any of this.
I hope this isn't a duplicate - I didn't find it in the forums.
Thanks,
Erik
Attachments:
Flaw Demo.vi ‏120 KB

Alex,
Thanks for the quick response on this. Again, the charts are awesome except for these minor fiddling details. Sorry about the terminology confusion - I didn't find anything in the Help system naming the legend buttons, and unfortunately I can't edit the prior post. When I said "AutoScale LocK" I meant "Scale Lock", and "AutoScale Once" I meant "Autoscale".
Here are the issues, hopefully clarified:
1. If any chart elements have Scale Lock set, pressing the AutoScale button for any plot causes these other plots to autoscale as well. Note these are not plots with multiple Y scales, they're stacked plots with separate y-scales for each plot. Changing the "Advanced->Auto Adjust Scales" parameter had no effect on this issue.
2. If none of the chart elements have Scale Lock set in the scale legend, pressing the Autoscale button for the X-Axis has no effect if the x-axis was previously set to show all the data history but then panned such that some data falls of either side of the chart.
This may have been confusing, so here's a breakdown of the steps to re-produce the problem using the VI I previously attached.
a. AutoScale all elements of the chart, and turn off Scale Lock on all elements
b. Move the data to the right in the chart, so the left half of the chart area has no data (e.g., set the X-Axis range to -5 to 6 seconds)
c. Press the X-Axis AutoScale button. The X-Axis range will not change from where it was in (b).
3. The Y-Axis will also auto-scale when returning to the Chart tab if Scale Lock is enabled for the plot with the fix for the x-axis scale in place (restoring the Xscale.Range parameters from a local variable). If the fix is not performed, this doesn't happen.
4. Pressing the Scale Lock button on one of the plots causes the X-Axis scale to be lost IF there is data past the maximum displayed X-Axis range. It looks like it set the X-Axis to the same problem range as before the fix was in place. I don't know how to build an event case for this, except for possibly "Mousedown?".
One more:
5. Enabling Scale Lock on any plot auto-scales any other plot that has Scale Lock enabled (assuming the user changed the Y-Axis range from the previously auto-scalled range). Obviously this is linked to #1 above, but worth noting.
Thanks again, Alex!
Erik

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).
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How to view signal in a waveform chart in Labview Signal Express?

Hi,
I would like to view a signal in Signal Express 3.0 in a "waveform chart" but don't know how to do it and I am thinking that it may be impossible?
In Labview there are two ways of viewing data, either in a "waveform chart" or in a "waveform graph". The great thing with "waveform chart" is that it lets you define a history length and you can see the data move to the left (strip chart option) as the samples are being retrieved. It works perfect.
In Signal Express I can only select "XY graph" or "Waveform graph" by making a right-click the mouse but I cannot select "Waveform chart". Is it really true that it is not possible to view the data in a "waveform graph with Labview SE? (1 analog signal being read continuously, 100 samples to read at 1K rate)
Thank you in advance,
Enrique
Solved!
Go to Solution.

Hi Enrique,
You are correct that there is currently no waveform chart in SignalExpress. The closest thing you can get to, is recording the data as a log and then viewing it while recording (which I realize is not quite the same, interactive behavior).
For your last comment, you wrote "waveform graph", but I assume you meant to say "chart" there as well.
Sorry about this. We have recently been getting this request, so perhaps in a future version.
Phil

About waveform chart

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