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Table
2-10.
IEEE-488 Address
Mode
Message
Descriptions
(cont)
MESSAGE
DESCRIPT
ION
GET
Group Execute
Trigger
Trigger
The
GET message
is
ignored during Local operation. When
Operation
the GET message
is
received (during remote operation)^
the
Generator executes
a
command string that
has
been
preprogrammed with
the
Configure Trigger command
("CT").
The
operation
of
the GET
message
is
identical
to the
operation
of
the
Trigger
("TR")
command.
Undefined IEEE-488
Commands
All
undefined IEEE-488 commands are acknowledged
by the
Generator handshake
sequence^ but no
action
is
taken.
2-47.
GOING
FROM REMOTE TO
LOCAL
The
Generator
switches
from
remote
to local
mode
in
one
of the following ways:
The
IEEE-488
Go
To
Local
(GTL)
message
is
received, the
remote
enable
signal
REN
is
false,
or a
Return
To
Local
(rtl)
message
is
generated
by
pressing the front panel
[CLR
I
LCL]
key
(if
the
Generator
is
not
in
the
local
lockout
mode).
The
Generator
enters the local
lockout
mode
when
the
Local
Lockout
message
(LLO)
is
received.
The
Generator
exits
the local
lockout
mode
to
the
local
mode when
REN
is
false.
When
switching
from remote
to
local,
unprocessed
commands
in
the input buffer
are
processed
until
the
input buffer
is
cleared or a front panel entry
is
made.
Switching
to local
has
no
effect
on
the contents of the
output
buffer.
2-48.
Talk-Only
Mode
Figure
2-6
shows two
generators
connected
together with the
IEEE-488
Bus.
To
select
the talk-only
mode,
set
the
TALK ONLY
address switch
to
1
(up),
if
the
TALK-ONLY
address switch
and
the
LISTEN-ONLY
address switch
are
set to
1,
the
talk-only
mode
is
selected.
In the talk-only
mode,
the
listener,
remote/local,
service request,
device
clear,
and
device
trigger interface
functions
do
not
apply.
If
the talk-only
mode
is
selected,
the
Generator
is
always addressed
to talk
and
the front panel
ADDR
indicator
is
always
lit.
The
Step
Up
("SU")
or Step
Down
(''SD")
message
is
sent
when
the
[f]
STEP
or
[i]
STEP
front
panel keys
are pressed.
This output
is
not
buffered,
and
if
no
listener
is
connected
to
the
IEEE-488
Interface,
no
output
will
be
sent.
A
carriage return
followed
by
line
feed (with the
EOI
signal true) are
always
sent as the
end
of record.
2-49.
Listen-Only
Mode
To
select
the
listen-only
mode,
set
the
LISTEN
ONLY
address switch
to
I
(up).
If
the talk-only
address switch
and
the listen-only
address switch
are
set
to
1,
the talk-only
mode
is
selected.
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