Keithley 237

SECTION2
Operation
(lOjJA
and
under).
The
default
delay
is
separate from
the
user
programmed
delay.
The time
period
of
the
default
delay
depends
on
which
current
range
(source
or
measure)
that
the
Source Meas-
ure
Unit
is on.
The
default
delay
times are listed
in
Table
2-4.
The
delay
time
period
for each current
range
in
the table generally reflects
5
RC time constants
of
settling.
Table
2-4.
Default
Delay
·Range
Delay
Source
or
Measure
(msec)
lnA.
360
lOnA.
75
lOOnA.
20
lfJ.A
5
lOjJA
2
lOOJLA
0
lmA
0
lOmA
0
lOOmA
0
lA
0
"When
default
delay
is
enabled (ON),
the
total
delay
pe-
riod
before
each
measurement
includes
the
default delay
and
the
user
programmed
delay.
With
default
delay
dis-
abled
(OFF),
the
total
delay
period
includes only
the
user
programmed
delay.
However,
with
AUfORANGE
(measure) enabled,
the
default
delay
time
periods
will
be
imposed
even
with
default
delay
disabled (OFF).
Usually, default
delay
is
left
enabled
unless
you
are
try-
ing
to
optimize
a
test
for
maximum
speed.
In
that
case,
default
delay
is
disabled
and
the
lowest
user
pro-
grammed
delay
that
will
achieve acceptable results
is
used.
To check
the
status
of
default
delay
and
other
operation
menu
item
parameters,
simply
enable
MENU
and
use
the
rotary
knob
to
scroll
through
the
menu
items.
If
no
changes
are
to
be
made,
disable
MENU
to
return
to
the
source-measure
display
state.
2-38
Perform
the
following steps
to
change
the
status
of
de-
fault delay:
1.
With
MENU
enabled,
tum
the
rotary
knob
until
the
default
delay
is
displayed.
For
ex.unple,
if.default
delay
is
presently
disabled, the
follo·:Nlng
will
be
dis-
played:
OFF
DEFAULTDELAY
2.
Use
the
SELECT
buttons
to
change
the
status
of
de-
fault
delay.
SELECT~
enables default delay,
and~
SELECT
disables it.
3.
With
the
desired
status displayed,
press
Th"TER
The
next
menu
item
will
be
displayed.
4.
If
no
other
menu
actions
are
to
taken, disable
ME..l\TU
to
return
to
the
source-measure
display
state.
NOTES
1.
Cycling
power
will
not
affect
the
status
of
the
default
delay.
If
it
was
previously
disabled
(OFF),
it
will
power
up
in
the
disabled state. Conversely,
if
it
was
enabled,
it
will
power
up
in
the
enabled
state.
2. Factory initialization
will
enable
default delay.
3.
For
pulse
sweeps,
selecting
the
alternate
default
de-
lay
state
(onoroff)maycause
delay
times
to
be
recal-
culated
by
the
Source
Measure
Unit
in
order
to
main-
tain
the
programmed
ON
and
OFF
times.
IEEE-488
Bus
Operation
TheW
command
is
used
to
program
default delay.
WO
=
Disable
default
delay
Wl
=
Enable
default
delay
HP
BASIC
4.0
Programming
Examples:
OUIPUT
716;
"WOX"
OUIPUT716;
"WlX"
Disable
default
delay.
Enable
default
delay
Complete
information
on
the
IEEE-488
bus
and
this com-
mand
can
be
found
in
Section 3
of
this
manual