User manual

Part 5: IEEE 488.2 Programming Reference
Logical Data Blocks
Each waveform normally contains at least a Waveform Descriptor block and one data array block.
Additional blocks may also be present in more complex waveforms.
l Waveform Descriptor block (WAVEDESC) - This includes all the information necessary to
reconstitute the display of the waveform from the data, including hardware settings at the time of
acquisition, the exact time of the event, kinds of processing performed, your oscilloscope name and
serial number, the encoding format used for the data blocks, and miscellaneous constants.
l Sequence Acquisition Times block (TRIGTIME) - This is needed for sequence mode acquisitions to
record the exact timing information for each segment. It contains the time of each trigger relative
to the trigger of the first segment, along with the time of the first data point of each segment
relative to its trigger.
l Random Interleaved Sampling times block (RISTIME) - This is required for RIS acquisitions to
record the exact timing information for each segment.
l First Data Array block (SIMPLE or DATA_ARRAY_1) - This is the basic integer data of the waveform.
It can be raw or corrected ADC data or the integer result of waveform processing.
l Second Data Array block (DATA_ARRAY_2) - This is a second data array, needed to hold the results
of processing functions such as the following Extrema of FFT math functions.
Array Extrema FFT
Data_Array_1 Roof trace Real part
Data_Array_2 Floor trace Imaginary part
Note: The waveform template may also describe an array named DUAL, but this is simply a way to
allow the INSPECT? query to examine two data arrays together.
Inspecting Waveform Contents
Use the INSPECT? query to examine the contents of your waveform.
The waveform template explains the WAVEDESC block and other logical blocks that may be returned by
the INSPECT? query.
Tip: Use the TMPL? query to get a copy of the full waveform template on your oscilloscope.
You can access a readable translation of single entities in the Waveform Descriptor block by using the
query INSPECT? "<WAVEDESC variable>". A typical exchange might be:
Query: C1:INSPECT? "VERTICAL_OFFSET"
Response: "VERTICAL_OFFSET: -4.0000e-002"
Query: C1:INSPECT? "TRIGGER_TIME"
Response: "TRIGGER_TIME: Date = APR 8, 2016, Time = 10:29: 0.311462573"
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