today's digital storage oscilloscopes
have lots of waveform math and automatic
measurement capabilities
but sometimes determining which math
function and which measurement to use
for a particular measurement application
can be confusing
in this short measurement tip video i'll
show you
how to perform a frequency shift
settling time measurement
using the measurement trend waveform
math function
on an infiniivision x-series
oscilloscope
hi i'm johnny hancock product manager
for keysight infiniivision oscilloscopes
let's get started so here we see an rf
signal that's hopping
between two different frequencies you
can see we have a higher frequency here
and a lower frequency in this area here
what we want to do
is determine what the settling time is
when it changes
from a high frequency to a low frequency
and vice versa when it goes from the
lower frequency to the high frequency we
have a special math function that we can
do that with let's go into the math menu
i'll select the operator these are the
various waveform math functions we have
some are very simple like add subtract
multiply divide
then we have several transforms down
here toward the bottom of the list
is something called measurement trend
i'll select
measurement trend on a
frequency measurement so let me turn on
the frequency measurement
and turn on that waveform math function
and now i can rescale it so this purple
waveform here
is now plotting the frequency
measurement
across screen so it's plotting the
frequency on the vertical
axis versus time
on the on the time axis and it's time
correlated
to our signal that's hopping between
frequencies so what we can see here
is that it changes pretty slowly when it
goes from the lower frequency to the
higher frequency
looks like it's ramping up and then when
it changes
back down to the lower frequency it's
very quick
so let's make some measurements on this
purple waveform math function
so this right up here represents our
maximum frequency
let's measure that so i'll just select
max and it's right about 100
kilohertz let's select the minimum
and it's about 20 kilohertz so we're
hopping between 20 kilohertz
and 100 kilohertz now
it looks like it changes very quickly
when it goes from high to low
but what about from low to high simply
select
a rise time measurement and it will tell
us
the settling time by default from ten
percent
to ninety percent now i can change that
and maybe make it from five percent to
ninety five percent
or you can you can customize it or from
a specific frequency
to another specific frequency so right
now it's measuring about 280
microseconds for this settling time
and if i want to i could turn on the
measurement statistics and see the
variations
if you think you might have learned
something in this short video
to make you more proficient in
performing oscilloscope measurements
i invite you to view our other
infiniivision oscilloscope measurement
tip
videos to learn more about keysight's
infiniivision x-series oscilloscope
go to the url listed on your screen or
contact one of keysight's authorized
distributors
thanks and semper fi