Keithley 237 - Page 124

SECTION2
Operation
llO.OOV
RANGE
15.
To change the source range, use the
SELECT
buttons
to display the desired range. The following shows
the
11
V
range selected:
ll.OOOV
RANGE
Note: Selecting a fixed range that is lower than the
highest keyed-in source
or
bias value will result
in
the message
"VALUE OUT OF RANGE"
when
the
parameters are saved.
In
this
situation, the source
will
default to
BEST
FIXED
range.
16.
Press
ENTER.
The following message
will
be dis-
played:
SAVE?
ENTER/CANCEL
17.
At
this point, the keyed-in parameters can
be
entered
and
saved,
or
canceled. Perform one of the following
steps:
A.
To enter
and
save the keyed-in parameters, press
ENTER. The GENERATING SWEEP
message
will
be displayed.
Sweep
create will disable
and
the Source Measure
Unit
will
return to the
source-measure display state.
B.
To cancel the keyed-in parameters, press CAN-
CEL.
Sweep
create
will
disable
and
the Source
Measure
Unit will return to the source-measure
display state. The previously programmed
sweep parameters
will
prevail.
NOTE
2-72
The
on
and
off times for a pulse sweep define
the entire period of each pulse waveform. The
on
and
off times include the effects of integra-
tion rate, filter,
and
default delay.
If
the Source
Measure
Unit
is configured such that
it
cannot
run
fast enough to
output
pulses at the
pro-
grammed
on
and
off times, the message
"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 inte-
gration rate, less filtering,
and
by
disabling
default delay. Note that the message ''PULSE
TIME
NOT MET"
is always displayed
when
AUTORANGE is enabled (see paragraph
2.13).
+
+
2.19.8 Linear Staircase
Pulse
Sweep
Perform the following steps to create a sweep for a linear
staircase pulse waveform (see Figure
2-35):
1.
Select
the desired source (Source I Measure
V,
or
Source V
Measure
I)
and
disable autorange (meas-
ure)
if
it is enabled.
2.
Enable sweep create.
3.
Use
the
SELECT
buttons to display the linear stair-
case pulse sweep (as shown below).
LIN
STAIR
PULSE
4.
Press ENTER. The source level of the first pulse
(START)
will be displayed. For example,
if
the level
of the first pulse is currently set at
IV,
the following
will
be
displayed:
+1.0000
START
5.
To change the start level, key-in the value using the
keypad. A keyed-in value of
2V
is shown as follows:
+2
VOLTS
6.
Press ENTER. The source level of the last pulse in the
sweep
(STOP)
will
be displayed. For example,
if
the
stop level is currently
at
20V,
the following
will
be
displayed;
+020.00
V STOP
7.
To change the stop value, key-in the level using the
keypad. A keyed-in value of
SOV
is shown as follows:
+50
VOLTS
Note: Entering a stop value that
will
result in more
than
500
pulses
(1000
measurements)
will
cause the
message "BUFFER
FILLED" to be briefly displayed
when
the sweep is saved. When the sweep is run, it
will stop after the
SOOth
pulse measure point instead
of after the programmed stop level.
8.
Press ENTER. The staircase step value
will
be dis-
played. For example,
if
the step value is currently set
to 1
V,
the following will
be
displayed:
+
1.0000 V STEP
9.
To change the step value, key-in the value using the
keypad. The following shows a keyed-in step value
of2V: