HP 8753D - Page 635

T
able 12-1
shows the
memory requirements
of
calibration
arrays
and
memory
trace
arrays
to
help you
approximate
memory
requirements
.
F
or
example
,
add
the
following
memory
requirements:
a
full 2-port
calibration
with
801
points
(58
k)
the
memory trace
array
(4.9
k)
the
instrument state
(3 k)
The
total
memory
requirement
is
65.9
kbytes
.
There
is
sucient
memory
to
store
7 calibrations
of
this
type
.
However
,
the
same
calibration
performed
with
1601
points
and
2
channels
uncoupled
would
require
252
k
bytes:
a
full
2-port
calibration
with
1601
points
,
two
channels
,
uncoupled
(230
k)
the
memory
trace
array
(19
k)
the
instrument
state
(3
k)
Only
2
of
these
calibrations
could
reside
in
memory
before
the
available
memory would
be
depleted.
T
able
12-1.
Memory
Requirements
of
Calibration
and
Memory
Trace
Arrays
V
ariable
Data
Length
(Bytes)
Approximate
T
otals
(Bytes)
401
pts
801
pts
1601
pts
1
chan
1
chan
2
chans
Calibration
Arrays
Response N
2
6
+
52
2.5
k
5
k
10
k
19
k
Response
and
isolation
N
2
6
2
2
+
52
5
k
10
k
19
k
38
k
1-P
ort
N
2
6
2
3
+
52
7
k
14
k
29
k
58
k
2-P
ort
N
2
6
2
12
+
52
29
k
58
k
115
k
230
k
Interpolated
cal
Same
as
above
in
addition
to
regular
cal
P
ower
Meter
Cal
*
(N
y
2
2
2
number
of
channels
z
)
+208
1
k
1.8
k
3.4
k
6.6
k
Measurement
Data
Memory
trace
array
*
N
2
6
+
52
2.5
k
4.9
k
9.7
k
19
k
Instrument
State
#
3
k
3
k
3
k
3
k
N
=
number
of
points
*
This
variable
is
allocated
once
per
active
channel.
y
The number
of
points
that
was
set
at
the
time
the
cal
was
turned
on.
z
If the
channels are
coupled, this
number is
always
1.
If
the
channels
are
uncoupled,
this
number
refers
to
the
number
of channels
that
have
power
meter
cal
on.
#
This value may change with dierent rmware revisions
.
The analyzer attempts to allocate memory at the start of
a calibration. If insucient memory
is available
, an error message is displayed. It is
possible that the CMOS memory might be
fragmented due to the sequence of saving and deleting states of
various sizes
. So another
alternative would be to store the current state to disk and then
press 4
PRESET
5 . The analyzer
runs a memory packer which might regain some previously inaccessible memory
. If memory is
still inadequate, delete an instrument state and restart the calibration.
Preset State and Memory Allocation 12-3