Pendulum CNT-91R User Manual

Measuring Functions
The counter measures the time from when the
signal passes 10 % of its amplitude to when it
passes 90 % of its amplitude. The trigger lev-
els are calculated and set automatically.
Auxiliary parameters shown simultaneously
are Slew Rate (V/s), Vmax and Vmin
Fig. 4-16
Trigger levels for rise/fall mea-
surements.
For ECL circuits, the reference levels are 20
% (start) and 80 % (stop). In this case you can
use either of two methods:
1. Select the general Time Interval function
described above and set the trigger levels man-
ually after calculating them from the absolute
peak values. Then you can benefit from the
auxiliary parameters Vmax and Vmin. For
measurements made on input A, use the fol-
lowing settings:
Rise
Time:
Trig Level A = V
min +0.2(Vmax - Vmin)
Trig Level B = Vmin +0.8(Vmax - Vmin)
Fall Time:
Trig Level A = Vmin +0.8(Vmax -
Vmin)
Trig Level B = Vmin +0.2(V
max
- V
min
)
2. Select one of the dedicated Rise/Fall Time
functions, and exploit the possibility to man-
ually adjust the relative trigger levels (in %)
when Auto T
rigger is active. Both input
channel menus are used for entering the levels,
but only one channel is the active signal input.
See the paragraph on Auto Trigger (page 4-19)
to find out how overshoot or ringing may 71B-
fect your measurement.
Pulse Width A/B
The function menu designation is Pulse.
Either input A or input B can be used for mea-
suring, and both positive and negative pulse
w
idth can be selected.
—
Positive pulse width means the time be-
tween a rising edge and the next falling
edge.
—
Negative pulse width means the time be-
tween a falling edge and the next rising
edge.
The selected trigger slope is the start trigger
slope. The counter automatically selects the
inverse polarity as stop slope.
Duty Factor A/B
The function menu designation is Pulse.
Either input A or input B can be used for mea-
suring, and both positive and negative duty
factor can be selected. See the preceding para-
graph for a definition of positive and negative
in this context.
Duty factor (or duty cycle) is the ratio between
pulse width and period time. The counter
determines this ratio by first making a pulse
width measurement, then a period mea-
surement, and calculates the duty factor as:
Pulsewidth
Duty factor =
Period
USER MANUAL ● CNT 9x Series ● Rev.22 February 2020
4-17

Pendulum CNT-91R Specifications

General

Brand	Pendulum
Model	CNT-91R
Category	Measuring Instruments
Language	English