time stamping data every 10 minutes

[baseball07]

Hi, I am collecting data points on a microprocessor every 30 seconds, saving it on the chip, then sending the data at once to LabVIEW every 10 minutes. My question is how to plot this data on LabVIEW as a function of when the data was actually collected. If I send it all at once every 10 minutes, the timestamp applied to that data would be the time it was sent in, not the actual time it was collected. Is there anyway I can plot it as a function of the time it was actually collected?

[joaopam]

Hello

Can you please post your actual VI? I got some ideas, but I need to see if they are valid in your case.

Regards

[RTSLVU]

If you can not timestamp it at the time it was taken you could always timestamp the last sample at the current time then subtract the sampling interval from that to generate a timestamp for the remaining.

This of course will only work if your sampleing interval is constant and ther is no delay or you know the delat time betwean when your last sample is taken and when you "send it to LabView"

[baseball07]

This is my current vi, it reads in 4 bytes of data and plots/saves the information.  Yes I was thinking of timestamping the incoming data then subtract the interval, but I was not sure if that was the best way to do it.  How do I time-stamp the incoming data? Right now "Write to measurements" just plots the data as a function of seconds after the vi started.  How can I save to excel the time/date?

[RTSLVU]

Here is a vi I made to write a single dimension numeric array to a file and add a timestamp in Excel (OLE) format.

[baseball07]

Thanks.  This vi will not open because it was made with a later version.

[RTSLVU]

What version are you using?

Have you tried saving the snippet to a vi in LabView?

I also forgot to mention, in Excel this timestamp is going to look like number until you format the column as time or date.

[baseball07]

Ok I will try this. I have LabVIEW 2010 SP1. I know the time intervals of my data coming, so you think time-stamping then performing computations on that is the best way to do it?

[RTSLVU]

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@baseball07 wrote:

Ok I will try this. I have LabVIEW 2010 SP1. I know the time intervals of my data coming, so you think time-stamping then performing computations on that is the best way to do it?

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Why not send the data everytime it is taken instead of saving it and transfering it in a bunch? Then you could timestamp each sample as it arrives and you would also have realtime graphing. Or set up a timer on your micro and you could at least have elapsed time sent with your data.

But anyway here is my vi saved in LV-10

[baseball07]

I am doing it this way because I am trying to conserve power. The transmitter is Bluetooth, so if I transmit real time data, the transmitter is always on and eating up power. What I did was save my real time data to the microcontroller, and then transmit everything after some time has elapsed, say 10 minutes. Now I need to relay this data back to real time on lab view.