The Hp Interface Bus; Hp-Ib Lines And Operations - HP 7470A Interfacing And Programming Manual

important for you to be aware of the HP-IB functions implemented on
each device in your HP-IB system to ensure the operational compati­
bility of the system.
The HP Interface Bus
HP-IB Lines and
Operations
The HP Interface Bus trans- °EV'°E A lfigtjnzij
fers data and commands be- |'"'t'en'°a'na(';'- .___
tween the components of an ;f.,§,,;,.
instrumentation system on <e~g-.
calculaior)
16 signal lines. The interface
functions for each system
component are performed
, , DEVICEB Dam BY"?
within the component so
Transfer
Able to talk
only passive cabling is aodhslen c°m'°'
needed to connect the sys— (e.g,
tems. The cables connect all mummeter)
instruments, controllers, and
other components of the sys— Genera'
tnterface
tem in parallel to the signal DEVICE 0 Management
lines. Onlyable to
_ . hsten
The eight Data I/O lines (8g_Sygna|
(DIO1 through DIO8) are 9e"e'a10'>
reserved for the transfer
of data and other messages
in a byte-serial, bit—paral1el DEVICE D
manner. Data and message
transfer is asynchronous,
coordinated by the three
handshake lines: Data Valid
(DAV),Not Ready For Data
(NRFD), and Not Data
Accepted (NDAC). The other
Only able to
talk
(e g counter
IFC
five lines are for manage- Q23
ment of bus activity. See the '25?'
figure on the right.
HP-IB Signal Lines
Devices connected to the bus may be talkers, listeners, or controllers.
The controller dictates the role 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-4 AN HP-IB OVERVIEW V