HP 54501A Programming Reference Manual page 338

The standard delay measurement
occurs
when in the
standard mode
(not
user-defined) and
is
not
a
jitter measurement.
standard
delay
=
mid-threshold of the
first edge of
second
parameter
minus mid-threshold
of
the first edge of the first
parameter
Note
Negative delay
is
possible
User defined
delay
=
second channel edge minus first
channel
edge
+
width
The
+
width algorithm
has standard and user-defined
considerations.
if
first
edge
is rising
then
+ width
=
mid-threshold crossing of first falling edge
•
mid-threshold
crossing
of first rising
edge
else
+ width
=
mid-threshold crossing of
second falling edge-
mid-threshold
crossing of first rising
edge
User-defined
is
the same
as
Standard definition except user-defined
threshold.
HP 54501A
Programming