...
.
THE HP-IB
What Is The HP-IB
The Hewlett-Packard Interface Bus is an easy to use, high performance bus struc-
ture that links the 3314A and other instruments, desktop computers and minicom
-
puters into automated measurement systems. The HP-IB is a worldwide instrumen-
tation interface standard (IEEE Standard 488-1978, ANSI Standard MC 1.1 and
IEC Recommendation 625·1).
How Does The HP-IB Operate
All of the active interface circuits are contained within the various HP-IB devices.
The interconnecting cable is entirely passive. The cable's role is limited to connec-
ting all of the devices in parallel, so that data can be transferred from one device
to another.
Every participating device must be able to perform at least one of these roles:
TALKER, LISTENER, or CONTROLLER. A TALKER transmits data to other devices
called LISTENERS. Most devices can perform both roles, but not at the same time.
A CONTROLLER manages the operation of the bus system by designating which
device is to Talk and which device(s) are to Listen at any given time
.
The 3314A
can be a Talker and a Listener, however, it has no Controller capabilities.
The minimum HP-IB system consists of one TALKER and one LISTENER without a
CONTROLLER. In this configuration, data transfer is limited to one direction
because one device must be manually set to "TALK ONLY" and the
,
other device
must be manually set to
LISTEN ONLY". The 3314A can be set to Listen Only,
but not to Talk Only
.
The full flexib
ility
and power of the HP-IB is realized when a controller is added to the
system. An HP-IB controller participates in the
when programmed to
schedule measurement tasks, set up instruments, monitor the measurements, and
analyze the results.
All examples in this section use the
-
hp-
9000 Series 200/300 computer and the BASIC
4.0 programming language.
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