Keithley 237

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SECTION3
IEEE-488
Reference
Device-dependent
Commands
a.s
DEVICE-DEPENDENT
COMMAND PROGRAMMING
IEEE-488 device-dependent
commands
are
the
most
important
commands
associ-
ated
with
instrument
programming
because
they
control
most
instrument
operating
modes.
The
IEEE-488
bus
actually treats these
commands
as
data,
in
that
they
are
sent
with
the
A
TN
line false.
All Model
236/237/238
front
panel
operations (such
as
trigger configuration
and
creating
sweep
lists),
as
well
as
some
operations
not
available from
the
front
panel
(like SRQ
and
terminator)
can
be
programmed
with
these
commands.
Command
Syntax-
Each
command
is
made
up
of
a single
ASCIT
capital letter fol-
lowed
by
one
or
more
numbers
or
letters representing
an
option
or
numeric
parame-
ter
of
that
command.
For example,
the
integration
time
can
be
set
over
the
bus
by
sending
the
letter "S" followed
by
a
number
representing
the
integration time
op-
tion.
SOX
would
be
sent
to
program
a
416J..1Sec
integration time.
Some
commands
have
two
or
more
parameters
that
must
be
separated
by
commas.
For example, a T4,0,0,0X
command
programs
a trigger configuration.
In
this case,
the
4 selects a trigger origin,
while
the
0
parameters
select
what
effect
an
input
trigger
has
on
the
instrument,
when
an
output
trigger
is
generated
by
the
unit,
and
whether
an
output
trigger
is
generated
at
the
end
of
sweep.
Parameter
values for
output,
measured,
and
compliance levels
can
be
designated
either
of
two
ways,
even
within
the
same
command:
•
Scientific notation,
or
exponent
form,
where
SE-3
represents
Sm
V
or
SmA.
• Real
numbers,
where
.005
represents
Sm
V
or
SmA.
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3-11