Specifications

A switch executive is an
external software package
that provides the following
features:
• Switch management
and report generation
• Creating switch paths
callable from any test
program
• Simplify configuration
of switching paths
• Mutual exclusion
between channels avoids
unwanted collisions
• Graphical end-to-end
routing between test points
• Typically works through
IVI driver supplied by
instrument vendor
The 34980A/L4445A provides
the critical parts of this func-
tionality related to switching,
and it provides features not
available in a switch executive:
programmable delays between
channel closings and control
of Analog and Digital Outputs.
A clear weakness of a switch
executive: it is only as good as
the information you program
into it. If channels in the sys-
tem are not wired properly,
you won’t get proper operation.
The 34980A/L4445A provides
ease of verification of wiring
through its Web Server, and it
can be used to configure and
test measurement setups.
Those switching setups can be
named and called later from
any programming environment.
You have both visual and total
execution control of switching,
and you gain execution speed
since a sequence of switch
closings stored within the
34980A/L4445A is ready to
execute from a relatively
short ASCII command.
Here is how you might
configure a 34980A/L4445A
test system:
• Wire instruments and DUT
test points via switch modules
• Use the graphical Web Server
to verify each channel is
connected properly
• Manually close channels
to connect instruments to
DUT for a measurement
• If necessary, note the need
for time delays between
channels for settling
• When you have the correct
measurement setup, save that
as a named sequence
• Repeat that operation until
you have all setups created
and named
• Call the named sequences
from your test program
A good example use of the
sequencer is assigning a
sequence to select an attenua-
tor path. Attenuators typically
have 3 to 4 sections to include
or exclude different degrees of
attenuation. This means you
would have to issue up to 4
open or close commands to
select a particular attenuation
setting. The name "ATTENUA-
TOR_60DB" could be assigned
to a sequence of opens and
closes that will select the prop-
er attenuation. You don’t have
to remember which channels to
open or close! Here’s what the
SCPI command would look like:
":ROUT:SEQ:TRIG ATTENUATOR_60DB"
As a test engineer, there are
few around that know the sys-
tem better than you. If you
manually verify and configure
the measurement switch
sequences, there is no need to
worry about outputs colliding.
Mutual exclusion is guaranteed
by your expertise! The pro-
grammer’s job becomes sim-
pler, and the speed of the sys-
tem is enhanced when using
sequences.
30