Glossary
TDS 620A, 640A, & 644A User Manual
NOR
A logic (Boolean) function in which the output of the OR function is
complemented (true becomes false, and false becomes true). On the
digitizing oscilloscope, that is a trigger logic pattern and state func-
tion.
OR A logic (Boolean) function in which the output is true if any of the
inputs are true. Otherwise the output is false. On the digitizing oscillo-
scope, that is a trigger logic pattern and state function.
Oscilloscope
An instrument for making a graph of two factors. These are typically
voltage versus time.
Peak Detect acquisition mode
A mode in which the oscilloscope saves the minimum and maximum
samples over two adjacent acquisition intervals. For many glitch-free
signals, that mode is indistinguishable from the sample mode. (Peak
detect mode works with real-time, non-interpolation sampling only.)
Peak-to-Peak
Amplitude (voltage) measurement of the absolute difference between
the maximum and minimum amplitude.
Period
A timing measurement of the time covered by one complete signal
cycle. It is the reciprocal of frequency and is measured in seconds.
Phase
A timing measurement between two waveforms of the amount one
leads or lags the other in time. Phase is expressed in degrees, where
360 Wave-
forms measured should be of the same frequency or one waveform
should be a harmonic of the other.
Pixel
A visible point on the display. The oscilloscope display is 640 pixels
wide by 480 pixels high.
Pop-up Menu
A sub-menu of a main menu. Pop-up menus temporarily occupy part
of the waveform display area and are used to present additional
choices associated with the main menu selection. You can cycle
through the options in a pop-up menu by repeatedly pressing the
main menu button underneath the pop-up.
Positive duty cycle
A timing measurement of the ratio of the positive pulse width to the
signal period, expressed as a percentage.
Positive overshoot
Amplitude (voltage) measurement.