How I do I program my oscilloscope to get waveform data?
There are two waveform query types, WAVFRM? And CURVE?
The WAVFRM? query returns a preamble followed by a binary block. The preamble contains data that you need to properly scale the data back into volts and seconds.
The CURVE? query also returns a binary block. The CURVE? Query returns only the binary block. It does not return a preamble. This makes it a little faster than the WAVFM? Query and is typically used after the preamble values have been obtained one time. The preamble values will remain the same until your program changes the settings of the scope. The data comes in a 2-byte format. The data will be in 1-byte or 2-byte per sample point format depending on the setting of theDATA:WIDTH parameter. When averaging or hi-res acquisition modes have been selected, the increased resolution is conveyed in the 2-byte data. In other acquisition modes there will be no significance in the use of 2-byte data.
The binary block structure consists of #xyyynnnn…..LF, where the x value represents the number of y bytes. The y bytes represent the record length. The n values are the digitizing levels for each sample and the block is terminated by a linefeed character.
With a 5,000-point record length, this means a 10,000-byte chunk of data. For example, if you had a 10,000 point record length, then the block would be #510000nnnnnnn…..LF.
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