Tektronix 2221 - OPTION 10 GPIB; Interface Response To Interface Messages

บ
Options and
Accessories
-- 2221
Operators
The talk
function
is
placed
in an
idle state
when the
oscilloscope receives the UNT message . In this state , the
instrument cannot
transmit data via the
interface
bus .
SRQ
Indicator —
Indicates the
communications
option
requires
service by the
controller
.
Service
requests are
cleared when the
instrument
has
been
polled for its
status and
no further
warning
or
error
conditions are
pending .
The
communication
option
asserts
a
power - up
service request ( SRQ ) when turned on . Other service
requests are asserted as enabled by the RQS and OPC
commands .
ADDR
Indicator
-
indicates
the
instrument
is
addressed
to
talk or listen .
PLOT
Indicator -
indicates
the
communication
option is
currently sending waveform data over its interface and
acquisitions
are
inhibited .
INTERFACE CLEAR ( IFC )
-When
IFC is
asserted
,
both the Talk and Listen functions are placed in an idle
state and the CRT ADDR indicator is turned off . This
produces the same effect as receiving both the UNL
and
the
UNT
messages
.
DEVICE
CLEAR
( DCL
) The
DCL
message
reinitial
izes communication between the instrument and the
controller . In response to DCL , the instrument clears
any input and output messages as well as any unexe
cuted control
settings
. Also
cleared are
any errors and
events
waiting
to be
reported
(
except
the
power - on
event ) . If
the SRQ line
is
asserted for any
reason
( other than power - on ) , it becomes unasserted when
the DCL message is received .
SELECTED
DEVICE
CLEAR (
SDC )
— This
message
performs the same function as DCL ; however , only
instruments that have been listen - addressed respond
to SDC .
u
Instrument
Response To
Interface
Messages
OPTION 10
GPIB
.
The
following
explain
effects
on
the
oscilloscope of standard interface messages received from
a remote
controller
.
Message
abbreviations used are from
ANSI / EEE
Std
488-1978 .
LOCAL
LOCKOUT (
LLO
)
—
Local
Lockout is
not
supported by the
instrument
. In
response
to
a LLO
message via
the
GPIB
interface ,
Option 10
generates
an
SRQ
error .
SERIAL POLL
ENABLE AND
DISABLE ( SPE AND
SPD ) --
The
Serial Poll
Enable ( SPE )
message
causes
the
instrument to
transmit its
serial - poll
status
byte
when it is talk - addressed . The Serial Poll Disable
( SPD )
message
switches
the
instrument back
to its
normal
operation .
1
REMOTE
ENABLE ( REN )
-When Remote
Enable is
asserted and
the
instrument
receives its
listen
address
,
the
oscilloscope is
placed
in
the
Remote
State
(
REMS
) .
When
in
the
Remote
State
,
the
oscilloscope's Addressed ( ADDR ) indicator is lit.
بلا
Reset
Under Communication
Option Control
Some oscilloscope modes may be set to their default or
power - on states
by sending
the INIt
command via the
communication
option
.
The
major
settings that
are
affected
by
INIt
are :
Unasserting REN causes
a
transition to LOCS ;
the
instrument
remains in
LOCS as long
as REN is
false .
The
transition
may
occur
after
processing of a
different
mes
sage has
begun . In this
case
,
execution of the
message
being processed is not interrupted by the transition ,
V
GO
TO
LOCAL (
GTL
)
-Instruments
that
are
already
listen
-
addressed
respond to
GTL by
assuming a
local
state .
Remote
- to - local
transitions
caused
by
GTL do
not
affect
the
execution
of
any
message
being
pro
cessed
when
GTL
was received .
ACQUISITION REP : AVE
ACQUISITION HSREC : SAMPLE
ACQUISITION LSREC : PEAKDET
ACQUISITION SCAN : PEAKDET
ACQUISITION ROLL :
PEAKDET
ACQUISITION SMOOTH : ON
ACQUISITION
WEIGHT
: 4 (
16 in the 2220
and 2221 )
ACQUISITION
NUMSWEEP
:
ACQUISITION VECTORS : ON
DATA
ENCDG :
BINARY
DATA
SOURCE
: ACQ
DATA
TARGET
:
REF1 (
REF4
in
the 2220
and 2221 )
PLOT GRAT : OFF
PLOT
FORMAT
: <
power -
on
setting
>
READOUT ON
Menu
system
reset .
MY
LISTEN
AND
MY
TALK
ADDRESSES
(
MLA AND
MTA ) . The primary Talk / Listen address is established
as previously explained in the GPIB Parameter Selec
tion
information .
UNLISTEN (
UNL
)
AND UNTALK (
UNT
)
— When
the
UNL
message is
received
,
the
oscilloscope's listen
function is
placed
in
an idle
(
unaddressed )
state . In
the
idle
state
, the
instrument
will not
accept
commands
over
the
bus .
u
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