Memory management in displaying large amount of data

[AB@17]

Hi

I have a requirement to display large amount of data in front panel in 2 table & 7 charts over period of time 100hrs,for 3 channels,the data read from channels has to be written into binary file,then converted and displayed in front panel for 3 channels respectively .

If I am getting 36 samples after conversion for every 1 hour,till 83 hrs 2388 samples displayed in table and charts,the data is fine and samples are matching exactly.

After 90 hrs 45 minutes delay is observed based on theoretical calculation of samples,what could be the issue

I have PXI8108 dual core controller with 1 GB ram

[DFGray]

This can be done in a relatively straightforward way.  If you have not read the LabVIEW help documentation on dealing with large data sets (Memory Management for Large Data Sets), you should do so before proceeding.  The basics are as follows:

1. Do not plot more data than your display can render.  For example, it does no good to plot 2 million points on a chart if your display only has 1500 pixels of resolution.  Decimate your data for display as mentioned in the LabVIEW help.
2. Use your file as a data buffer.  Write all your data to a binary file (TDMS, flat binary, or HWS are all well supported in LabVIEW).  If needed, you can maintain a display buffer in memory, or just recreate it every time it changes.  There are many different ways you can do this.
3. Do no write any more data to a listbox or multicolumn listbox than is actually displayed.  You can scroll by using a separate scroll bar and regenerating data based on what the scroll bar settings currently are.

Good luck.  Let us know if you need more info.

[JÞB]

this KB article goes into the details that DFGray highlighted

[DFGray]

That KB was integrated into the LabVIEW help a few years ago, which is why the remains dated.  Unfortunately, it appears that the code that goes with the KB has been deleted and does not appear to ship with LabVIEW.  You can pick up a copy of it here.

One further note - neither the KB nor the LabVIEW help topic mention the data value reference.  It should be used instead of single-element queues in almost all cases.

[AB@17]

I have read all those things and but here the issue that, all data has to be displayed no other alternate

so i have to solve issue in this condition only

[AB@17]

What I have observed,as long as labview is running;labview memory consumption is increased and memory in RAM left for Conversion and executing VI is minimizing time to time, so it is taking time for conversion as the RAM space is minimized

so queue is filling

[DFGray]

My apologies for not reading your original post more closely.  The amount of data you are working with is actually relatively small.  You should be able to plot over a million points on a LabVIEW graph in under a second with your hardware.  Something else is going on.  Please post your code so we can take a look.

[AB@17 · Accepted solution]

As DFGray,

said there is no problem with RAM or Display,problem with conversion (timming issue )if i am converting large amount data it is taking same, compared to converting less amount of data.So i have modifed in such way that every 1Sec data is convereted at once,issue resolved

Thanks for your Replies