Table of Contents
Operation
Model
8672A
Sending the Status Byte
Message
(Cont'd)
3-60. The RSV (Request
Service)
bit
is
true when¬
ever
any of the four conditions
that
cause
a
re¬
quest
for
service
exists (even
during the first 50
ms
after
a
programming
change).
Once the Synthesizer
is
addressed
to
talk, the RSV
line
is
latched even
though the Synthesizer's need for
service
may
have changed.
3-61. The
status
byte
is
useful
for determining
when
a
given
programming
change
has
been
exe¬
cuted.
For example,
if
the Synthesizer
is
addressed
to
talk immediately after
a
frequency
change,
the
status
byte
can be used
to determine when the
Synthesizer
has
re-acquired
lock.
A
frequency
change might be
followed by
a
status
byte
sequence
of 72, 72,
and
then
64,
indicating the Synthesizer
is
now
locked.
3-62.
Sending
the Status Bit
Message
3-63. The
Synthesizer outputs
a
status
bit on
one
of
the
Bus
data
lines
in
response
to
a
parallel/poll
(see
controller manual). The
line
is
switch
select¬
able
(see
Section
II)
as is
the
level
of
the bit's logic.
The
status
bit
represents
the
RSV bit of
the
status
byte.
3-64.
Receiving the
Abort
Message
3-65. The Synthesizer
stops
talking or
listening
when it
receives
the
Abort
Message.
3-66. Programming Quick
Reference Guide
3-67. Table 3-10
shows
program
string
syntax,
program
codes and
arguments, and the status byte.
All
possible
program
codes
(including equivalent
duplicates)
are
shown, but the recommended
codes
are indicated
with
boldface type.
3-68.
Programming Examples
3-69. Figure 3-7
is
a
flowchart showing how
to
program
all
of the
Synthesizer functions and
the
twelve
bus messages in
HPL (9825 computing
con¬
troller),
and
BASIC (9830 computing controller).
3-20
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