Instructions for Downloading Data from the TDS220 Oscilloscope to Computer.

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 Procedure:

  1. Connect the TDS220 to an intermediate lab computer (one of the 75 MHz pentiums.)  Use a GPIB cable to connect the GPIB ports on the backs of the scope and computer.
  2. Start LabVIEW on the computer.
  3. Within LabVIEW, open the program called "TDS220.vi" located in the C:\LABVIEW\TDS220.llb library (this library is only accessible from LabVIEW.)
  4. Data is collected from the scope by clicking on the right arrow button located in the upper left hand corner of the TDS220.vi window.

Comments:

Always use the "hand" tool when using the mouse to manipulate the front panel of "TDS220.vi" (the "hand" can be selected by clicking on the hand button at the top of the TDS220.vi window.)  The pointer and other tools are for editing the program only.

In order to save the data to a file, you will need to flip the "Save to file?" switch to "YES" and specify a valid path and filename in the "Path and name of savefile:" box.  The save file is a text file consisting of columns of numbers separated by tabs.  This format allows easy export to spreadsheet or plotting programs (such as Origin 4.1 which is on one of the pentiums.)  If you downloaded a single channel from the oscilloscope, there will be two columns of data.  The first column is time in seconds, and the second is voltage in volts.  If you downloaded both channels there will be 4 columns in the savefile.  Since both channels use the same time axis, columns 1 and 3 will be identical, column 2 will be the CH1 voltage and column 4 the CH2 voltage.

When the program is run, the oscilloscope will automatically be put in "stop" mode if not already in that mode.  This has the effect of causing the scope to freeze.  To get the scope running again, push the "run/stop" button on the front of the scope.

The time and voltage offsets set on the oscilloscope will not appear in the data sent to the computer.  The program subtracts the offsets from all downloaded data  (the computer, however, will only receive data that is visible on the scope's display, so feel free to use the offsets to make center the trace you are interested in on the scope's display.).

If an error occurs, make sure your path and filename of savefile are valid.  Also check that the oscilloscope is turned on and displaying the data you wish to download.



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