How to log 15 min. of constantly overwritten data to Lookout?

[GeoDesigns]

I would like to set it up so that Lookout (version 4.5) will store only the last 15 min. of recorded data for a desired variable. That is, as the most recent data is added to the Excel spreadsheet, the oldest points of data are deleted. Is there any way to set this up in Lookout?

[AndreOliveira]

Hi,

You could use the Sample object in Lookout, this object keeps an array of the last 35 samples. The way it works is the following, every time a datamember goes high the object acquires a new value and discards the last value of the array.
Now as you need to store the last 15 min of data, you need to find out what is the frequency at which your data is being sampled from wherever you are getting this data from. If your sample frequency is such that 35 elements in the array is not enough to accomodate it, you can make a chain of Sample Objects and get as many samples in the "buffer" as you need, you can accomplish that by just writting the last sample of one object to the first element of the next Sample Object.

Now, in order to log the data accordingly
to the Spreadsheet file I would use DDE connection, that simplifies the application and updates the data as it changes.

I hope it helps

Regards

Andre Oliveira