Fluke PM6685R Outdoor Timer User Manual


 
Sense Command
Subsystems
Depending on application, you can select
different input channels and input charac
-
teristics.
n
Switchbox
In automatic test systems, it is difficult to
swap BNC cables when you need to mea-
sure on several measuring points. With
PM6680B/1 you can select from three
different basic inputs (A, B and E), on
which the counter can measure directly
without the need for external switching
devices. With PM6685 you can select
from two different basic inputs (A and E).
n
Prescaling
For all measuring functions except fre-
quency, the maximum input A frequency
is 160 MHz.
To extend the range for frequency mea-
surements, PM6680B and PM6685 can
divide (scale) the input A frequency by
two, while PM6681 scales by four.
When using channel 1, the counter auto-
matically selects this scaling factor when
measuring FREQ A, giving 300 MHz
max frequency for PM6681 and PM6685,
and 225 MHz for PM6680B.
For all other measuring functions, and for
frequency if you select negative slope,
the counter does not divide the signal and
the max repetition rate is 160 MHz.
Using the Subsystems
Sense Command Subsystem 6-13