HP 3468A - Page 45

Bit
1
is
true
if
an
invalid
combination
of
function
and
range
codes
are
sent
to
the
3468A,
e.g.,
F2R5.
It
is
cleared
when
a
valid
range
and
function
combination
is
selected.
Bit
O
is
cleared
when
the
reading
is
read,
a
program
command
is
executed
that
changes
the
state
of
the
A/D
converter,
or
a
Trigger
command
is
received.
The
Status
Byte
together
with
the
Service
Request
(SRO)
Mask
determine
when
the
Require
Service
(ROS)
bit
is
to
be
set.
Setting
ROS
causes
SRO
to
be
sent
on
the
HP-IL.
Execution
of
the
INSTAT
command
for
the
3468A
will
clear
SRO
and
it
will
remain
clear
until
another
reason
for
setting
ROS
occurs.
ROS
on
the
other
hand,
is
set
if
one
or
more
corresponding
bits
in
the
Status
Byte
and
SRO
Mask
are
both
set.
ROS
is
cleared
whenever
all
corresponding
bits
are
not
both
set.
IN-
STAT
then,
may
cause
RQS
to
be
cleared
but
not
in
all
cases.
Bits
2,
4,
5,
and
7
are cleared
with INSTAT.
Let’s
look
at
three short
examples
of
how
the
INSTAT
command
can
be
used.
The
first
two
examples
will
be
used
later
in
a
Statistics
program.
Example 1. Data Ready
The
data
ready
bit
(bit
O
in
the
Status
register)
of
the
3468A,
allows
the
calculator
to
determine
when
new
measurement
data
is
ready.
Since
the
data
ready
bit
is
bit
O,
it
will
be
placed
into
the
calculator’s
Flag
OO
when
the
INSTAT
command
is
executed.
Therefore,
Flag
OO
will
be
the
flag
tested
to
see
if
data
is
ready.
Before
keying
in
the
following
example,
make
certain
that
the
3468A
is
in
the Single
Trigger
mode.
Keystrokes
HP
41
Display
Comments
XEQ] [ALPHA] INSTAT [ALPHA 1.0000 Bit O is set indicating Data
Ready. The value of this bit is
eee
FS?]
00
YES
The
test
to
see
if
Flag
00
is
set returns
a YES answer
XEQ]
[ALPHA]
IND
[ALPHA
The
display
will
show
the
3468A reading.
The data is no longer available.
It was read into the calculator.
Bit O is cleared and INSTAT
returns a ‘‘O”’.
([XEQ] [ALPHA] INSTAT [ALPHA] 0.0000
FS?|
00
NO
The
Flag
test
now
shows
that
bit O in the status
register
is
clear.
40