~
HP
5384A and
HP
5385A
SYSTEMS
•
u Ope,atoon
and
Pmg,amm;ng
3-133.
In general, the controller can read the counter
Status Byte at any
time
to
check selected operating
conditions.
During
remote
operation,
you may
selectively program the
counter
Service Request
Mask
(SMnnn)
to
identify
the
conditions
which
you
feel may
require
service
or
data
collection.
3-134.
Once
SRQ
has
been sent,
the
controller
can
identify
which
condition
or
conditions
caused the
Service Request
by
reading
the
Status Byte.
When
the
Status Byte
is
read,
conditions
that
exist
will
be
setto
1
whether
or
not
enabled
as
a
condition
to
generate
SRQ.
Sending a
"rds
(703)"
with
the
HP
9825A,
or
"A=SPOll
(703)"
with
the
HP-85A requests
the
eight-
bit
binary status byte. The
number
returned
will
be a
decimal
equivalent
to
the
sum
of
the
different
status
bits set,
as
shown in Table 3-8.
3-135. For
example; the
instrument
requested serv-
ice
(SRQ)
and reading the Status Byte
returned
a value
of
"97".
This can be
interpreted
as
64
+
32
+ 1 =
97,
meaning
the
SRQ
FlAG
is
set,
power
is
on,
and data
is
ready. The bits
of
the
Status Byte are set regardless
of
the
Service Request Mask.
However,
if
that
bit
is
masked
out,
it
will
not
generate an SRQ.
3-136. Service Request Mask
3-137.
Upon
receipt
of
the Service Request Mask
Command
(SM
Command),
the
instrument
will
load
the
binary
value
of
"nnn"
into
the
service request
mask register. The
SRQ
line
bit
will
be
"set"
if
a
bit
in
the
status
byte
becomes set and the
corresponding
bit
in
the service request mask
is
set.
To
specify
the
service request mask, send
the
SM
command,
·fol-
lowed
by the decimal
number
that
represents
the
sum
of
the
bits
that
you
want enabled.
You
may send any
number
between
"0"
and
"255",
although
only
the
five least significant bits are used. The binary value
of
"nnn"
is
interpreted
as
follows:
BIT
MEANING
NOT
MASKABLE
Bit 7 Always 0
...............
.
Bit 6
SRQ
...................
.
Bit 5 Power
On
..............
.
MASKABLE
BITS
(DECIMAL)
WEIGHT
128
64
32
Bit 4
Instrument
in
local
. . . . . .
16
Bit 3 Always 0 . . . . . . . . . . . . . . . . 8
Bit 2 Error
or
Fail
Condition
. . . 4
Bit 1
Always 0 . . . . . . . . . . . . . . . . 2
Bit
0 Data Ready . . . . . . . . . . . . . . 1
For
example, sending
the
command
"SM5"
will
generate a service request
(SRQ)
after
an
error
3-16
Table
3-8.
HP 5384A
and
HP 5385A Status Byte
07
06
05 04
03 02
01
DO
0
SRQ
POWER
LOCAL
0
ERROR
0
DATA
FLAG
ON
or
READY
FAIL
128
64
32
16
8
4
2 1
or
fail
condition
or
data
is
ready
(4
+ 1
).
Sending
the
command
"SMO"
masks
off
(or disables) all
SRQ
conditions. The
condition
or
conditions
which
caused
the
service request may be
determined
by reading
the
Status Byte.
3-138. DEVICE DEPENDENT
COMMANDS
3-139. The
counter
will
accept
command
strings in
either
upper
or
lower
case.
Spaces, commas, and
semicolons between commands are
interpreted
as
command
terminators. In
addition,
parity bits
will
be
ignored.
Depending
upon
the
controller,
this can
help
to
speed-up
programming.
The
following
free
format
command
statements
will
produce
identical
results:
OUTPUT 703; "FU1,AT1,FI1,Ml1,GA2,DN"
OUTPUT 703; "fu1,at1,fi1,ml1,ga2,dn"
3-140. Output Formats
3-141. Data
is
output
to
the
HP-IB in
the
following
format:
ALPHA
CHARACTER
I 1
CHARACTER
I
MEASUREMENT
EXPONENT
DATA
FIELD !3
CHARACTERS!
1 13 CHARACTERS 1
<N
SPACES>±
<J
DIGITS>·
<K
DIGITS>
Alpha
character
Variable
number
of
blanks
+or-
sign
Digit
Decimal Point
Variable
number
of
digits
E
+or-
sign
One
exponent
digit
Carriage Return
line
Feed
•
•
•
To Next Page
Loading...
Need help?
General
