Graph - time?

hi
I have a small problem with the "waveform graph" - what I want is the X-axis to diplay the time (this is easy:-) ) but I want the time to start at Zero and the display seconds from when I start the VI?? when I choose "relative time" its displaying seconds but not from zero?? - another thing: the data displayed in the graph I also write to a spreadsheet file and I then use the "tick count [ms]" which is also written to the spreadsheet in order to get a "timestamp" for each datapoint!! this works ok! but isent there someway that the graphblock can give the timestamp?? hope you understand what I mean??

Hi Viller,
I still didn't get it all, but if you don't have a timestamp for every Y-value, you need to create it for yourself. For an example I made a solution in the simple and the cool way:
Greets, dave
Message Edited by daveTW on 02-27-2007 11:56 AM
Greets, Dave
Attachments:
Example_BD.png ‏7 KB

Similar Messages

Wavefrom graph time from .csv file

Hello everyone. I had this problem something about three weeks ago:
http://forums.ni.com/t5/LabVIEW/Wavefrom-graph-time-from-csv/td-p/2256754
and solved it by changing the delimiter to a comma decimal delimitter with the format %,;%.2f
But this problem occurs again suddenly!.
I have attached the VI and the .csv file as a ZIP format
Best regards
Oesen
Attachments:
Trykmaaling_READ.vi ‏36 KB
ekstra.zip ‏1 KB

I have deleted "row 0" and the graph is better now, but is still incorrect
Best regards
Oesen

Graphing time

I am trying to get numbers to graph time -- (either line or bar). I have the following in two cells
34m
1h1m
These two values were derived by subtracting two different start/end times -- e.g. the time in each cell is (end time-start time)=elapsed time. I'm trying to plot this on a graph. No matter what settings I choose the graph doesn't display -- any help?
PS - I've changed the scale, tried to convert the time to 34 and 61 in plain number format to no avail.
Thanks

Thanks - my choice of words was not very precise. FYI the cells are the subtraction of two times - hence the duration. What's curious is numbers defaulted the format to hours minutes, which is convenient (what I wanted without any formula manipulation) -- but it won't let me format them into something different (eg whole number) which the graph should pick up. Even through indirect reference and attempts are reformatting don't graph properly.
Thanks for the reply, however.

Wavefrom graph time from .csv

Hello everyone
I use "read from spreadsheet file" to read a two column .csv file in a waveform graph.
Time is defined in the first column and the Data is defined in the second column.
The problem occurs in the x-axis of the graph (Time-axis). It doesn't match with the numbers from the .csv as shown on the picture below, but the Y-axis has correct values.
The VI is uploadet
Best regards
Oesen
Solved!
Go to Solution.
Attachments:
2-Column CSV.vi ‏13 KB

Works fine here once I configure it to use a comma as decimal delimiter (using format=" %,;%.3f " on read from spreadsheet file).
You seem to use a foreign version so that should not be necessary, depending on the language setting of your computer but it seems to be the problem.
As a first step, you should display the entire 2D array in an array indicator to ensure that your number don't get truncated somehow. If they get truncated, dt will be set as zero and thus ignored and taken as 1.
LabVIEW Champion . Do more with less code and in less time .
Attachments:
SetDt.png ‏23 KB

Graphing Time Data

I have a report that pulls data from a phone system database. Each record has the amount of time spent talking, waiting, holding and ringing for each person as numeric fields showing the total number of seconds for a block of calls. I've been able to create the report and write formulas that convert the seconds for each field into a time field. But of course it converts it to a specific date which is not what I really want. If they run the report for a large time period like a month, then there will likely be more than 24 hours in the hour position which the function trucates to a single day.
As a work-around I've been able to use formulas to calculate the number of hours/minutes/seconds and then create more formulas to calculate the summary and grand totals for each person. Not the best solution, but it works. My problem is that now they would like to add a graph to the report showing the average total time spent on the phone for each person.
Of course I can't graph my calculated time since the formulas result in a String value. And it doesn't seem to want to let me sum a time field so I can graph a true time value either. I thought maybe I could convert my finished average time per person into a time value at the group level since that wouldn't be over 24 hours, but that didn't work either.
Was hoping someone would have some experience in working with time data. Any suggestions would be helpful.

Hi Jay,
Thanks for the response, but I don't think I explained my problem clearly. Here's how my data is stored (sorry about the lack of columns, so I separated them with "|"):
Phone Rep ||   Day   ||   Talk Time ||   Hold Time || Total Time
John Doe   ||    1-1-09 || 5,000 sec||   1,200 sec   || 6,200 sec
John Doe   ||    1-2-09 || 6,000 sec || 2,000 sec ||   8,000 sec
Total          ||             11,000 sec || 3,200 sec || 14,200 sec
The read out on the report should read:
Phone Rep   ||   Total Talk Time ||   Total Hold Time || Grand Total Time
John Doe      ||     3:03:20       ||          0:53:20       ||        3:56:40
Avg/day        ||     1:31:40         ||        0:26:40          ||     1:58:20
When I convert the time in seconds to a time variable with TimeSerial(hh,mm,ss) it gives me the time in the correct format, but it's listed as simply a time of day. If the report runs for many days, then the time values could require the hours to go over 24 such as 155:35:26 to reflect a month's worth of calls. My formulas that calculate the read out as shown above can do this with no problem. The problem occurs when I try to graph the average at the bottom. I can't seem to find a way to chart the average time per day.
I've tried summing the total time in a group and then find a way to format the y axis to show the time format. I've tried creating a formula to convert the individual record into a time format and then summing that for the graph, but it doesn't give me the option to sum, only to count or other non-numeric options. I've also tried creating a formula to convert the finished average calculation into a field that can be graphed by itself, but when I insert the chart it doesn't list my formula in the available fields to graph.
I would even be willing to create the chart in a sub report that somehow pulls in just the total average and then tries to graph that, or use the Microsoft OLE chart object to try and push the data to that and insert the finished chart, but having never done either of these, I was hoping for an easier solution.
Thanks
Edited by: Ken Skinner on Jan 25, 2009 8:55 PM
Edited by: Ken Skinner on Jan 25, 2009 8:59 PM

Graph time axis start zero

Hi
I acquire signals from a USB card (N signals), I use de DAQmx Analog input (NchanelsNsamples) ,I dont know how i can start the time axis at zero..
please you can help me
thanks

Hello Alexandra,
If you are using a graph, you have just to double-click on the first value to change it.
If I don't answer your question, please give me more information.
Regards.
Jean-Baptiste C.
National Instruments France
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>> Téléchargez dès maintenant toutes les présentations techniques !

Bar graph time change

Hello Forum Members
In the attached vi a graph simply plots two values side by side in bar format. What I would like to see happen, and need some assistance with is:
1. Any bars plotted to remain on the graph for historical visualisation
2. When the date changes, another two data points will present themselves to the graph, and I would like to plot these next to the previous plot group (with a space in between the two plot groups)
Thats it. Would anybody be able to show me this? I've looked through the previous posts, but have been unable to find something close enough to my requirement
Thanks and best regards
Ray
ps....does anybody see the red line at the bottom of the second (white) bar (at the 0 x point, and across the width of the plot)......what is this artifact?
Attachments:
graph_forum.vi ‏13 KB

Hi Rayclout,
I created a sample program for you. It doesn't follow the exact same architecture
as your original code. It does however produce what you have laid out in your
post.
I used an event structure inside a while loop instead of for loops. This
architecture allows the user to record data after every input. The data points
are stored as a 2D array which is displayed in a waveform chart. The main difference
between a waveform chart and a waveform graph is that the waveform chart
stores its data history.
The thin line at the bottom of the bars in your graph is due to the fact that
there is still a data at 0. I was able to hide it by assigning a -1 constant
to the array and uncheck auto scaling in the y axis chart of the waveform chart properties.
It's not perfect, but this should give you a good start.
I hope it helps.
Josh L.
Applications Engineer
National Instruments
Attachments:
Bar_Graph_Example.vi ‏16 KB

Times displayed in graphs are 2 hours behind

Hi,
Not sure where to adjust this, but all performance graphs within OPSCenter on every asset is two hours behind (also the live graphs) time on the system is configured as CEST. The only time i needed to specify something in relation to a timezone was during installing OPSCenter configuring ASR credentials.
Cannot find any info in the documentation in regards to this.
Thanks in advance
Kind regards
Patrick

Updated to 12.1.1 issue solved

Graph stalls when front panel is adjusted

So I am trying to debug a code that someone previously wrote. I am a bit familiar with the code but as I mentioned did not write it myself. The deal is that when Im in running the front panel and the graph is graphing time vs any other parameter, if you press any button on the front panel or if a sub-vi gets called the graph will stall and one has to manually reset the graph. I am not too sure why this is going on. Attached are a few screen shots of where this section of the code lives. There is a stacked sequence with two subdiagrams and it is also being called in the event structure inside one of those subdiagrams. I could also upload the whole code if needed.
Thanks for the help guys
Attachments:
Graphing front panel.doc ‏456 KB

OK, I was able to get to the code by selective unzipping.
As a first step, you should eliminate all these value property nodes and replace them with plain local variables instead. The code os causing excessive thread switching and spends way too much time in the UI thread.
Overall, there is way too much code. For example you have in the "graphed parameter" event the same property node in every single case of the inner case structures. These property nodes belong after the case structure, only once instance each needed!
(Sorry, I have to do some other things now. Will look at it a little more later.....)
LabVIEW Champion . Do more with less code and in less time .

How to display X value against a particular Y value in XY graph

Hi labview gurus,
I've a XY graph, time is plotted in X axis and amplitude is plaotted in Y axis, I want to display the value of X at a particular value of Y. Please let me know how to do this programatically.
VI Attached.
Attachments:
testplotv8.5.vi ‏55 KB

Hi guy,
I want to display the value of X at a particular value of Y.
- Find the index of your "particular Y value". Then use this index to index the corresponding X value…
- Use a cursor in your graph…
Is there a reason to use SystemIdentification functions to load simple spreadsheet data?
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Time Vs current reading ploting error

Dear all.
I am trying to plot instantaneous graph time VS current. I am getting data properly . But i could not able to see the time on x axis. Can some one suggest what need to configure to get x axis data.Which option need to enable . or any changes need to
be made.
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Dim rnd As New Random
Static counter As Integer = 0
Static average_sum As Double = 0
Static Avg_count As Integer = 0
Dim Power As Double
Static Cc_count As Long = 0
Static watt_hour As Double = 0
Dim Counter_write As Integer = 60
Static WH As Double = 0.0
Try
SerialPort1.Write("c")
System.Threading.Thread.Sleep(250)
Dim ACS_CS As Double = CDbl(SerialPort1.ReadLine())
Dim voltage As Double = 24.0
voltage_text.Text = CStr(voltage)
ListBoxSensor.Text = CStr(ACS_CS)
Power = (ACS_CS * voltage) / 3600
Display.Text = CStr(Power)
WH = WH + Power
If WH > 1000 Then
WH = 1.0 + WH
End If
WH_text.Text = CStr(WH)
' The code to plot instantenous curve.....................................................................
Dim current_val As Double = ACS_CS
Dim r As DataRow = dT.NewRow
r("time") = Now
r("current") = current_val
'add the row
dT.Rows.Add(r)
''remove any row older than 1 minute
'Dim oldestTime As DateTime = Now.AddMinutes(-1)
'Do While DirectCast(dT.Rows(0)("time"), DateTime) < oldestTime
' dT.Rows.RemoveAt(0)
'Loop
''finally bind the chart....
Chart1.DataBind()
' record data into excel sheet...............................................................................
counter = counter + 1
If counter = 2 Then
Dim headerText = ""
Dim csvFile As String = IO.Path.Combine(My.Application.Info.DirectoryPath, "Current.csv")
If Not IO.File.Exists((csvFile)) Then
headerText = "Date,TIME ,Current,voltage, Watt-Hour, "
End If
Using outFile = My.Computer.FileSystem.OpenTextFileWriter(csvFile, True)
If headerText.Length > 0 Then
outFile.WriteLine(headerText)
End If
Dim date1 As String = "24-10-2014"
Dim time1 As String = CStr(TimeOfDay())
Dim current_1 As String = CStr(ACS_CS)
Dim voltage_1 As String = CStr(voltage)
Dim watt_hour1 As String = CStr(Power)
Dim x As String = date1 + "," + time1 + "," + current_1 + "," + voltage_1 + "," + watt_hour1 + "," + vbNewLine
outFile.Write(x)
End Using
End If
If counter > 2 Then
counter = 0
End If
Catch ex As Exception
' MsgBox("Error in Timer1_Tick: " & ex.Message)
End Try
End Sub

Hi AMPS12,
This is a forum for Visio, not for Visual Studio. You’d better post this issue in Visual Studio forum.
http://social.msdn.microsoft.com/Forums/vstudio/en-US/home?category=visualstudio
The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you
for your understanding.
Best regards,
Greta Ge
TechNet Community Support
It's recommended to download and install
Configuration Analyzer Tool (OffCAT), which is developed by Microsoft Support teams. Once the tool is installed, you can run it at any time to scan for hundreds of known issues in Office
programs.

Position Vs Time for LVDT

Hello I'm very new to Labview (Three weeks) Can anyone give me some sample on how to measure position vs time for LVDT? This is very simple using an Oscilloscope by position X1 and X2 cursors to measure delta time but I am not sure how to do this with the labview graphs or charts. I want measure time from trigger to fist sign of movement, total stroke time and snubbing time (Of actuator). I have attached an image of what I want to measure. Are there specific VIs to look for these times. Even by manually placing cursors on desired position in labview all I get is the time for each cursor but not the delta time between cursors. Any help will be greatly appreciated
Juan
JCollado
Solved!
Go to Solution.
Attachments:
measuringStrokeTimejpg.jpg ‏77 KB

Thanks for your help.
I have attached the VI I'm working on. It is working manually as far as the graph time measurement. No database connection and other controls not in use yet.
I am also thinking that I might be able to do this with the shift register checking if current value for Y is higher then last. If higher I should take trigger time to this time and so on.
It will take me a bit because I'm so new to labview and new to Instrumentation type programming.
Thanks
JCollado
Attachments:
highFlowDecreaseSimulationeEventcovi.vi ‏25 KB

Passing array taking lots of time

Dear all,
i am working on an application where i need 3 huge size(2 with 6,00,000 and 1 with 18,00,000 elements). i pick data from my H/W after 25 ms. process the data and display it on the graph.
time of processing is very less - just 2-3 ms. the most time consuming part in the algo is passing the array into the cluster. just passing(excluding the processing part) the array into the cluster takes arnd 40 ms.
i am attaching a vi here. i am just taking the time diff b/w reading the array from the cluster and writing it back.
pls have a look at it and let me know why is it taking so much of time for just passing the array.
thanks,
Ritesh
Attachments:
speed test.png ‏54 KB

DFGray wrote:
The reason your timing changes when you convert your control to a constant is that you are timing the write to the control as well as the write to the cluster. Look carefully at your data flow. It has a couple of major issues in the timing.
The start value can possibly be generated any time before or after the cluster is written. There is nothing to determine this time. You can easily solve this by running your data wire through the case structure instead of just connecting it.
The end value can be generated either before or after the write to the control. In your case, the compiler seems to have put it after the control write. You can solve this the same way.
A better way is to use the structure johnsold used. However, you will probably get a zero if you don't use a loop to do it many times, since the operation is probably comfortably under a millisecond. Loop multiple times and divide the final result by the loop count to get your answer. Be aware that if you are using a desktop operating system (such as Windows XP or Windows 7), other processes can easily preempt your process, adding extra time. Shut down all extraneous processes and do it several time, taking the shortest number.
I would recommend you read Managing Large Data Sets in LabVIEW. Then read the LabVIEW help on the In Place Element Structure. You may also want to read up on the Data Value Reference. Let us know if you need more help.
Yes imporatant note!
Tip:
1) Get yourself a laptop with 8 cores and use Windows Task manager to figure which cores get used and which ones are mostly idle.
2) Put your benchmark code inside a Timed Sequence structure and use the property node to run the Benchmark in one of the idle cores.
Works for me!
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Problems to plot and write the aix of a 3d graph

Hi,
I habe replied a message with this but i am posting in a new mesage too.
I have posted some messages but anyone has solved my problem. I hope that, now you help me, because I am in a urgency.
I am working only with labview 5.1 because is the only version available in my lab.
Let's go to the problem:
I am sending the vi and the screenshot of my frontal panel with some changes that I need to do.
I have a table which will be part of my graph.
Time will be aix X, Termistors (1 to 4) will be aix Y and Temperature from each termistor will be aix Z.
I need to plot the correct time of my table in aix x of my 3d graph time. How to do this??I have use properties of garph,I did many things and I am still in this problem. (Resume: how to write hours:minutes:seconds in aix X)
The second problem is that I need to plot in the graph only the points .Example: in time 12:00:00 I will have 3 points. Point 1 -indicating time,temperature for termistor 1. Point 2-indicating time,temperature for termistor 2 and etc. Point 3 -indicating time,temperature for termistor3. What I want is the blue points in garph. But now I have some lines and tis wrong.
Later i will do fitting for each time with the points i got.
Please help me !!
I am in hurry,I am doing my job but now I found some problems. Let's change ideas.
Thanks a lot!
Rafael
Brasil
Labview 5.1
Attachments:
frontal panel with points.gif ‏30 KB
grafico 3d tabela 26 09 1.vi ‏1038 KB

I went through your previous posts, and I found that a few others desperately tried to help you, without much success. Ben has very accurately described what to you should do. I think that nobody here can do much more for you, since the solution to your problem has been given so many times.
However, I'll do one last attempt. This is about the time formatting of the X axis. Apparently, your problem comes from the fact that while everybody tells you to pass the time as a day numeric value, you are still trying to pass it as a string ! This comes from the fact that you retrieve your time value from the Get Time/Date String function, which is nice when one has to display the time, but not when one has to do some calculation or to plot the value. You should have noticed that there is another function that returns the time as seconds. Since time zero is in january 1904, the proper way to use this function is to read the time in second when your measurements are started, then to subtract the obtained value from all the readings. Then do what you have been told : convert it into fractionnal days by dividing by 24 and 3600. Then your plot will display the time starting at 00:00:00.
A few more words. I think your main problem is that you do not listen to the answers that others are giving you. You are just expecting somebody to come with a ready to use solution that fits exactly your needs. And even when this happens, you don't see it !!! Unless you come back with a convincing proof that you are really trying to understand what you are doing, and having a personal input in this, I'm afraid that you will not get any further help.
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...

Comment mettre un graphe à l'heure du systeme

Bonjour,
Je suis actuellement en stage et j'ai qql pb avec labview.
J'aimerais que l'axe des X de mon graphique se mette à l'heure du systeme lorsque je lance mon acqui. Je construit une wavaforme pour afficher mon graph, mon deltaT marche mais mon T0 commence en 1904. J'affiche un format H:MN JJ/MM/AA.Je suis sous labview 7.1.
Merci de votre aide
ITS31

Je dois manquer quelque chose.
Je pensais qu'en ajustant le t0 de la waveform le problème serait réglé, mais ce n'est pas le cas. Ce paramètre n'est pas pris en compte par le graphe (???).
Il faut modifier spécifiquement l'offset du graphe pour que l'affichage du temps soit correct.
Voir le vi attaché...
CC
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...
Attachments:
Set Graph Time.vi ‏29 KB

Graph - time?

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