Keithley 237

Step
4.
Define
Sweep
Parameters
The parameter
sweep
lists for all
the
available
sweep
waveforms are
provided
in
Figure 2-38
through
Figure 2-43.
Any
parameter
of
the
sweep
can
be
dis-
played using
the
rotary knob. Changes to all parameters,
except
points/
decade
and
range,
are
accomplished
by
using
the
keypad to key-in
the
value
and
pressing EN-
TER. Changes to
the
points/decade
and
range parame-
ters are accomplished
using
the
SELECT buttons to dis-
play
the
parameter option
and
pressing ENTER
When
a parameter value is entered (ENTER pressed),
the
next parameter
of
the
sweep
is displayed.
Note
that
when
the last parameter (range) is changed
(SELECT
pressed),
the other sweep parameters cannot
be
displayed
with
the
rotary knob.
When
a range parameter is entered (ENTER
pressed),
the
Source Measure Unit
exits the
sweep
list
and
prompts
the
user
to save
or
cancel
the
sweep
pa-
rameters.
Step
5. Save
Sweep
Parameters
In
order
to save
sweep
parameters,
the
message
"SAVE?
ENTER/CANCEL"
must
be
displayed. This message is
displayed after
the
range
parameter is entered.
It
can also
be
displayed
by
again pressing CREATE.
With
"SAVE?
ENTER/CANCEL" displayed, press EN-
TER to save the
sweep
parameters. The GENERATING
SWEEP
message will
be
displayed. Pressing CANCEL
will default
the
sweep to
the
previously
programmed
definition.
LEVEL
0
1'
NO.POINTS
-1,
DELAY
Rotary
Knob
BIAS
RANGE
Figure
2-38.
Fixed
Level
Sweep
Parameters
+
+
NOTES
SECTION2
Operation
1.
The
maximum
number
of measure points
in
a sweep
is
1000.
If
a
sweep
is defined such
that
it
exceeds
1000
points,
the
message
"BUFFER
FILLED" will
be
dis-
played briefly
when
the
sweep
is saved. The sweep
will default to
1000
points.
2.
When
a
sweep
is saved (step 5),
all
data
stored
in
the
buffer from
the
previous
sweep
is lost.
3. The
on
and
off times for a pulse sweep define
the
en-
tire period
of
each pulse waveform. The
on
and
off
times include
the
effects
of
integration rate, filter,
and
default delay.
If
the
Source Measure
Unit
is con-
figured such
that
it
cannot
run
fast
enough
to
output
pulses
at
the
programmed
on
and
off times,
themes-
sage
"PULSE
TIME
NOT
MET" will
be
displayed.
The
sweep
can
be
performed,
but
it
will
not
conform
to
the
programmed
on
and
off times.
Speed can
be
increased
by
using
a faster integration rate, less fil-
tering,
and
by
disabling default delay.
Note
that
the
message ''PULSE TIME
NOT
MET" is always
dis-
played
when
AUTORANGE is enabled (see para-
graph
2.13).
4.
A log
sweep
cannot
start
at
0
or
sweep
through
0.
If
a
sweep
is
programmed
to start
at
0,
it
will default to
one
count
on
the selected source range.
If
pro-
grammed
to
sweep
through
0,
the
message
"LOG
CANNOT
CROSS 0"
will
be
displayed
when
trying
to save
the
parameters. The
sweep
will
be
cancelled.
5. Entering a
STEP value
that
is less
than
the resolution
of
the
source
range
will default to a
step
value
of
zero. The source will never exceed
the
level
of
the
first
sweep
point. The
maximum
STEP value is twice
the
full scale
range
of
the
highest range
used
in
gen-
erating
the
sweep.
6.
Changing a
parameter
value (or source range) of the
currently saved
sweep
also affects
the
parameters
of
the
other
sweep
waveforms for
the
selected source
(V
or
I).
For example, setting
the
voltage
sweep
delay
Source
level; 0
to±
max source output
Measurement points;
0001
to
1000
Delay; 00.000
to
65.000
seconds
Bias level;
0
to±
max source output
AUTO, BEST
FIXED,
or
any fixed range
2-63