RCATS Downloads

Downloadable Excel Spreadsheet for Flight Testing Electric Powered Models with the RCATS Telemetry System

Editor’s note: on pages 48 - 54 of the January 2005 issue of Fly RC magazine, Tom Hunt reviewed the RCATS telemetry system (www.rcatsystems.com). In the article, he describes an Excel “macro” that he and Joe Cabana developed to average the raw data generated by the RCATS system within any one second period. This spreadsheet also computes input watts (from voltage and amperage) and rate of climb from averaged altitude changes. It includes an elapsed time column and presents battery amp hours consumed during a flight. This helpful tool makes it easier to assess the meaning of the data gathered by the system, even before it is graphed. Tom Hunt offers the following instructions for using the Excel macro.

Note: although the user does not have to have RCATS installed to "play" with these free downloads, the user MUST have Microsoft EXCEL loaded onto his or her PC.

Two files are required for this application. Both can be downloaded in ZIP format - simply "right-click" the following link, select "Save Target As," specify the place on your hard drive where you wish to locate the files and use WinZip (or some other "unzipping" software) to open and save the files to your hard drive.

RCATS Files

GetFlightData-electric.xls is a "start-up" Excel File macro that organizes and computes new values based on the acquired raw data from the RCAT system. You must download this file to your computer first. It can be put in any folder, but the most convenient is the RCATS directory created when the RCATS program is installed.

sample_data_file_from_RCATS.dat is a "raw data" file generated from the RCAT system. If you have not purchased and installed RCATS, you can download this file and use it to see how the EXCEL macro program works. Put it in the same directory that you put the GetFlightData-electric.xls file.

USING THE DOWNLOADS:

Once the files have been downloaded, launch the EXCEL file—GetFlightData-electric.xls. A new window will appear with the options: disable macros, enable macros, more info. Select the "enable macros" option.

Another new window appears asking you to select the RCATS raw data file. Note: if the directory that appears in the window is NOT the RCATS directory where the raw data is stored, you will need to change that directory using the facility at the top of this new window.

Select the raw data file.

Another new window appears titled: Select output items to show.

This allows the user to choose which collected or computed data to display. Check or uncheck the appropriate boxes (leave all checked until you fully understand how this macro works and what data you truly need to analyze the flight qualities of your model). Select "OK" in this box after the proper output items have been selected.

The EXCEL macro will now "read-in" the raw data and perform its magic.

Depending on how much data is collected and the speed of the PC processor, it may take from a few seconds to a minute or more.

When EXCEL is finished the read-in and computation, a small pop-up window will appear telling the user how many "packets" have been "dropped". This is usually a very small percentage (usually less than 1%). A "packet" is one data sample. If you consistently have a lot of dropped data packets, you may have a transmission or reception problem with the RCAT system. In many cases there may be no real fault with the system, it may have been some exterior interference, such as radio noise on or near operating range of the RCATS system.

Select the "ok" in the small window after noting the number of dropped packets. EXCEL will then prompt the user to "save" the file. Make sure that it is saving the data in the proper directory (usually the RCATS). Select the proper directory if it defaults to some other directory than RCATS.

Generally, the EXCEL Macro will remember the directory last used for "read" and "save". The very first time one uses the macro, the default directory may be something completely different and the user must point to the proper one.

Two spread sheets will now exist in this new EXCEL file appearing as "tabs" at the bottom of the window. They are called "average data" and "raw data" and should be self explanatory.

TROUBLESHOOTING

If Excel presents an error message indicating that its security level is blocking access to the RCATS file, close the error message and click on the Tools button in the taskbar. Select Options and go to the Security tab. Choose "low" security. Your Excel program will now open the RCATS file.

Good luck and happy data mining and analyzing! Please let me know if you have any problems using this application.

Tom Hunt, tomh@flyrc.com