Scatter chart for real-time tracking of a single cell value ?

[eastside877]

Hi. I use Excel 2003. On a spreadsheet connected to a DDE data feed, I
have a cell containing an integer number that updates and changes
constantly during the day.

I would like to chart the number in that cell in real-time second by
second between certain hours of the day. I have been told that it may
be possible to use a scatter chart to do this but I have not been able
to make it work or to find useful help files. It seems to me that the
problem has to do with charting a single cell rather than a range but
I'm not sure.

Any practical advice or pointer to a "how-to" web site would be very
helpful.

Thanks in advance

Joe

 

[Jon Peltier]

You can't get a single point plotted? Or you can't get a chart that shows
the current and recent values of the DDE value?

- Jon

 

[eastside877]

You can't get a single point plotted? Or you can't get a chart that shows
the current and recent values of the DDE value?

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutionshttp://PeltierTech.com
_______










- Show quoted text -

Hi Jon. Actually, the cell contains the sum of several DDE values. I
need a chart that will plot that value every second (or few seconds)
over several minutes or hours on a line chart. So it is the recent and
current values of the cell that I need to plot.

Joe

 

[Kelly O'Day]

eastside877

I have done what you want, charting process control data, several times.

The trick is to have an automatically updating dynamic data range where
your new data values go. You should capture the date-time as well as the
read. You can either have the DDE append your real time value directly to
the end of your dynamic data range, or have a worksheet based procedure
transfer the new value to the dynamic range whenever the DDE cell is
updated.

Your chart can then be set to plot the last 10, 100, or whatever number of
reads you want from the dynamic range. Your chart will update as soon as the
Dude value is written to your workbook.

Here's a link to example dynamic charts that I have on my site.

http://processtrends.com/TOC_dynamic_charts.htm

Kelly

http://processtrends.com

 

[Jon Peltier]

I've used event procedures to update a growing table of numbers, placing the
latest values at the bottom. You could grow this indefinitely, or remove a
row from the top every time you add one at the bottom. Setting this up to
run robustly is a trick; the dynamic charts based on the archived data are
pretty easy to handle.

- Jon

 

[eastside877]

eastside877

I have done what you want, charting process control data, several times.

The trick is to have an automatically updating dynamic data range where
your new data values go. You should capture the date-time as well as the
read. You can either have the DDE append your real time value directly to
the end of your dynamic data range, or have a worksheet based procedure
transfer the new value to the dynamic range whenever the DDE cell is
updated.

Your chart can then be set to plot the last 10, 100, or whatever number of
reads you want from the dynamic range. Your chart will update as soon as the
Dude value is written to your workbook.

Here's a link to example dynamic charts that I have on my site.

http://processtrends.com/TOC_dynamic_charts.htm

Kelly

http://processtrends.com








- Show quoted text -

Great! I am going to check your web site and experiment. Thanks for
the help, it's much appreciated.

Joe

 

[eastside877]

I've used event procedures to update a growing table of numbers, placing the
latest values at the bottom. You could grow this indefinitely, or remove a
row from the top every time you add one at the bottom. Setting this up to
run robustly is a trick; the dynamic charts based on the archived data are
pretty easy to handle.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutionshttp://PeltierTech.com
_______








- Show quoted text -

Thanks a lot for the help. Much appreciated. I looked up (and
marked your web site. Lots of good stuff there.

It looks like between your and Kelly's advice I should be able to
figure out something now.

Thanks again,

Joe