HP 1630A User Manual

Model 1630A/D/G

An
HP-113 Overview
10 . The Status Bit
Message - A byte that represents the operational
conditions of a group of
devices on the
bus . Each device
responds on a particular bit of the bytethus
identifying a device-dependent
condition .
This
bit
is
typically sent by devices in response to
a parallel poll operation .
The Status Bit Message can also be
used by a controllerto specifythe
particular bit and logic
level that a
device will respond
with when a parallel poll operation is
performed . Thus more than
one device can
respond
on the same bit .
11 . The Pass Control
Message - This transfers the bus management
responsibilities from
the active
controller to another
controller .
12 . The Abort Message
- The system controller sends this message to
unconditionally assume
control of
thebus from the
active controller . This message terminates all bus
communications (but
does not
implement a Clear
Message) .
These messages
represent the full implementation of all HP-113
system capabilities . Each
device in a system
may be
designed to use only the messages that are applicable
to its purpose in the system
. It is important for
you
to be aware of the HP-113 functions implemented
on each device in your HP-113
system to ensure the
operational compatibility of the system .
THE HP INTERFACE
BUS
HP-113
Lines And Operations
The HP Interface Bus transfers
data and commands
between the components
of an instrumentation system
on 16 signal lines . The
interface functions for each system
component are
performed within the component soonly
passive cabling is needed
to connect the systems . The
cables connect all
instruments, controllers, and other
components of the
system in parallel to the signal lines .
The eight Data
I/O lines (DI01 through D108) are reserved
for the
transfer of data and other messages in a byte-
serial,
bit-parallel manner . Data and message
transfer is
asynchronous, coordinated bythe
three handshake lines :
Data Valid (DAV), Not Ready
For Data (NRFD), andNot
Data Accepted
(NDAC) . The other five lines are for
management
of bus activity . See the figure on the
right .
Devices connected to
the bus may be talkers, listeners, or
controllers .
The controller dictates the roll of each of the
other devices
by setting the ATN (attention) line true and
sending
talk or listen addresses on the data lines .
Addresses
are set into each device at the time of system
configuration either by switches built into the device or by
jumpers
on a PC board . While the ATN line is true, all
devices
must listen to the data lines . When theATN line is
false,
only devices that have been addressed
will actively
send or receive data . All othersignore
the data lines .
9872-R-173-1
1 . . .8
DAV
NRFD
NDAC
IFC
ATN
SRQ
REN
EOI
Several listeners can be active simultaneously but
only
one talker can be active at a time . Whenevera talk address
is put on the data lines (while ATN is true),
all othertalkers
will be automatically
unaddressed .

HP-113 Signal Lines
B-
3
e .g .
multimeter)
UNIONISM
MARMEM
111111
General
Interface
DEVICE C
00
1U// "
Management
MIMS
Only able to
MOM
010141101011111
listen
(e .g ., signal
generator)
mmomomem
1111111
V
DEVICE D
able
Only
to moss
talk MEMO
11001111111
le .g .,
counter)
011011021011011
MOINEEM
10101210101011010
DIO
DEVICE A
Data Bus
(8 Lines)
Able to talk,
listen, and
control
(e .g
.
calculator)
Data Byte
DEVICE B
Transfer
8~l~
Control
Able to talk
and listen

HP 1630A Specifications

General

Brand	HP
Model	1630A
Category	Measuring Instruments
Language	English