Tektronix 2221 - Page 79

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Options and
Accessories -
2221
Operators
ADVANCED
FUNCTION
MENU
( for
the 2230
only
)
NON
-
VOLATILE
EXTENDED
MEMORY
(
for
the
2230
only
)
C
The
following
functions
are
available as part
of the
ADVANCED
FUNCTIONS
Menu on
2230
instruments
con
taining
either the GPIB
or the RS - 232
- C option .
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When
either
Communications
option
is
installed in the
2230 DSO , extra battery - backed memory is also installed .
Waveforms
stored in the
extra
memory
may
be
protected
from
overwriting or
deleting
(
locked ) using
the
Advanced
Functions menu .
Commands that are
available via the
communications
interface
can
also
lock
that
memory
space . Memory spaces may be also made “ permanent " via
the
Communications interface
.
Permanent
waveforms
cannot be
overwritten ,
unlocked , or
deleted by the
opera
tor
with
the
Advanced
Functions
menu
.
a
REFERENCE -
Allows
non - volatile SAVE REF
memory to be
copied
,
deleted
, or
protected .
I
COPY
-
Selects and
copies
one
non -
volatile
SAVE
REF
memory
to
another
SAVE REF
memory
.
Waveforms
stored in
the lettered
extended
memory
locations
(
REFA
through REFZ )
must be
moved
to
one of
the
numbered
SAVE
REF
memory
locations
to be displayed . Waveform data to be retrieved
from
or
written to an
extended
memory
location
must go
through a
numbered
SAVE
REF
memory .
The extra
memory provides 26 Kbytes of
non - volatile
waveform storage space .
The
memory
is
divided into
1
Kbyte
locations
labeled
REFA
through
REFZ , but
the
number
of
actual
waveforms
that
may be
stored
depends
on the
acquired
waveform
record
length
(
1024
bytes
or
4096
bytes
)
and
acquisition
mode (
normal or
average ) .
Averaged
waveforms
require
two
bytes for
each point so
that an
averaged 1 K
waveform
needs
2
Kbytes
of
non
volatile
SAVE
REF
storage
and an
averaged
4K
waveform
needs 8
Kbytes
.
Specifications
for
the
non
volatile
Extended
Memory are
given in
Table 7-1 .
DELETE
-
Selects
non - volatile
SAVE
REF
memory and erases the stored data if not locked .
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PROTECT -
Selects
memory
space to
lock
or
unlock .
Locked
memory locations cannot
be
overwritten or deleted .
Via the
Communications
interface ,
extended
memory
locations
may be
per
manently protected to prevent them from being
overwritten
by
the
UNLOCK
DELETE
menu functions .
or
OPTION 10
GPIB
OPERATORS
INFORMATION
COMMAllows the
selection
of parameters for
optional
communications
options ,
when
they
are
present
The
GPIB
Communications
Option
complies
with
ANSI
/
IEEE
Standard
488-1978 . All
other
specifications for
the
instrument (
including the
performance
conditions ) are
identical to
those
specified in "
Specification " in
Section 1
of
this
manual .
DATA -
Selects
the
data
-
coding
format (
ASCII ,
HEX , or
BINARY
) , source
or
destination target of
the data
( ACQ ,
REF1
,
REF2
,
REF3 or
REF4
) , and
channel selection
( CH1
or
CH2 )
for
data
transmissions .
Standard
Functions
,
Formats ,
and
Features
The
interface -
function
capabilities
of
a
GPIB
instrument ,
in
terms of
interface
-
function
subsets , are
identified in
ANSI
/
IEEE
Std
488-1978 .
The
status of
subsets
applicable
to this
instrument with
Option
10
are
listed
in
Table
7-2 .
STOP
BITS -
Selects
the
number
of
stop
bits for
RS - 232 - C
data
transmissions .
(
Stop
bits
selected
by
interface
command
in the 2220
and
2221.
)
The
usual
choice
for
stop bits
is 1 , but
some
printers
/
plotters
require
two stop bits
for some
baud
rates
.
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FLOW
-
Sets the
data
flow
control over
the
inter
face ON and OFF . Binary waveform information
cannot be sent with FLOW ON .
The
GPIB interface
conforms to the
Tektronix
standard
on
Codes
,
Formats ,
Conventions ,
and
Features of
messages sent over the bus to communicate with other
GPIB
instruments .
Specific
format
choices
implemented in
this
instrument are
listed
in
Table 7-3 ;
specific
features
implemented are shown in Table 7-4 .
7-3