2.19 CREATE
SWEEP
The following paragraphs contain the information
needed to create a
sweep
for a selected waveform. Infor-
mation is organized as follows:
2.19.1 Parameter Definitions: Explains
and
defines the
various
sweep
parameters
that
are
used.
2.19.2
General
Procedure: Provides
the
general proce-
dure
for creating a sweep.
2.19.3 IEEE-488 Bus Operation: Covers the basics
needed to create a
sweep
over
the
IEEE-488 bus.
NOTE
The following outlined paragraphs provide
detailed step-by-step procedures for creating
a sweep for all the available waveforms. For
many
users,
the
abbreviated information
in
paragraph
2.19.2 (general procedure) is suffi-
cient.
2.19.4 Fixed Level
Sweep:
Provides the detailed proce-
dure
for creating a fixed level sweep.
2.19.5 Linear Staircase
Sweep:
Provides
the
detailed
procedure for creating a linear staircase sweep.
2.19.6 Logarithmic Staircase
Sweep: Provides
the
de-
tailed procedure for creating a logarithmic staircase
sweep.
2.19.7
Pulse
Sweep:
Provides
the
detailed procedure for
creating a pulse sweep.
2.19.8 Linear Staircase
Pulse
Sweep:
Provides
the
de-
tailed procedure for creating a linear staircase pulse
sweep.
2.19.9 Logarithmic Staircase
Pulse
Sweep:
Provides
the detailed procedure for creating a logarithmic stair-
case pulse sweep.
2.19.1
Parameter Definitions
The various programmable
sweep
parameters
are
de-
fined as follows:
Bias: Bias is
the
de
level
that
is maintained
at
the
output
(operate enabled)
when
a
sweep
is
not
in
progress. Also,
during
pulse sweeps,
the
output
goes to
the
bias level
+
+
SECTION2
Operation
during
off time periods (see Figure 2-34 through
Figure 2-36). The programmable bias level is from zero to
±maximum
source output.
Delay: This is
the
delay time set
by
the
user
for fixed
level, linear staircase,
and
log staircase waveforms.
At
the
end
of
each
programmed
delay a measurement is made.
Delay can
be
programmed
from
OO.OOOsec
to
65.000sec.
Delay is also
known
as
sweep
delay
and
user-pro-
grammed
delay.
Note
that
the
user
programmed
delay alone does not ac-
count
for
the
entire time length of
the
source-delay-meas-
ure
cycle.
Other
factors, such as default delay, range
change delays
and
the
measurement integration time
add
to
the
overall time
of
the
sweep
(see
paragraph
3.7.3).
Level: Level is simply the source level for fixed level
sweep
and
pulse
sweep
waveforms.
No. Points: This is
the
number
of
measurements
made
(1
to
1000)
during
a fixed level sweep,
and
the
number
of
pulses
(1
to
500)
during
a pulse sweep. Also
known
as
"count''
and
"pulses"
for IEEE-488 operation.
On
and
Off
Time:
On
and
off times are
used
for all pulse
sweeps.
On
time is
the
time
duration
at
each pulse level.
Off
time is
the
time
duration
at
the
bias level.
On
and
off
time can
be
programmed
from
0.001sec
to 65.000sec. For
IEEE-488 operation,
on
and
off times are
known
as
tON
andmw.
·
The
on
and
off times for a pulse
sweep
define the entire
period
of
each pulse waveform. The
on
and
off times in-
clude
the
effects
of
integration rate, filter,
and
default de-
lay.
When
a pulse
sweep
waveform is created, the
Source
Measure
Unit will calculate the delay times
needed
to sat-
isfy
the
programmed
on
and
off times of each pulse. The
calculated delay times
are
then
stored
in
the
sweep
buffer. These delay times can
be
acquired
by
examining
the
sweep
buffer (see
paragraph
2.24).
If
the
Source
Measure
Unit
is configured such
that
it
can-
not
run
fast
enough
to
output
pulses
at
the
programmed
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 integration rate, less fil-
2-61
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