User manual

MAUI Oscilloscopes Remote Control and Automation Manual
DD_OVERLAP_REF, DOVL
Description
This command sets a state variable which determines whether Byte Offset (when jumping to a "Worst
SAM #" or an NRZ mismatch position) or other disk-drive related features re-establish the overlap of the
reference signal whenever they move the head trace. To re-establish overlap, they calculate correlation
over a window around the expected match position, and overlap the waveform at the sample where the
correlation is highest. The size of the window is limited to the width of the head trace display or to a fixed
number of bytes, whichever is smaller. If the waveform is greatly different within the window, the most
correlated position may not be meaningful, and the waveforms will not appear overlapped. This should be
clear on the display.
The command DD_OVERLAP_REF ON does not cause the reference to be displayed. The next change of
Byte Offset, etc, causes the reference to be displayed, correctly overlapped.
The command DD_OVERLAP_REF OFF does not cause the reference trace to be turned off. It may be
turned off, or repositioned as desired by the user. Subsequent changes to Byte Offset, etc, do not move
the reference and do not cause it to be displayed.
Command Syntax
DD_OVERLAP_REF <bool>
<bool>: = {OFF, ON}
Query Syntax
DD_OVERLAP_REF?
Response Format
DD_OVERLAP_REF <bool>
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