Keysight 81160A - Page 658

Appendix
658
Pulse Width
Interval between leading and trailing edge medians:
The specified and displayed value is that obtained with fastest edges,
essentially equal to the interval from the start of the leading edge to the
start of the trailing edge. By designing so that the pulse edges turn about
their start points, the interval from leading edge start stays unchanged (in
practice, start points may shift with changes in transition time) when
transition times are varied. This is more convenient for programming and the
width display is easy to interpret.
Pulse Delay
Interval between leading edge medians of trigger output pulse and output
pulse:
The specified and displayed value is that obtained with the fastest leading
edge. Pulse delay has two components, a fixed delay from trigger output to
output signal and a variable delay with respect to the trigger output.