HP 8712C, Руководство пользователя, Страница: 369 / 559

I
Front/Rear Panel
Connectors
As many
as 14 instruments
can be connected to the analyzer
(15 total instruments in the system). The cables can be interconnected in
a star pattern (one central instrument with the HP-IB cables emanating
from that instrument like spokes on a wheel), or in a linear pattern (like
boxcars on a train), or a combination of the two. See Figure
in Chapter 1.
There are certain restrictions that must be followed when interconnecting
instruments:
l
Each instrument must have a unique HP-IB address, ranging from 0 to 30.
l
In a two-instrument system that uses just one cable, the cable length
must not exceed 4 meters (13.2 ft).
l
When more than two instruments are connected on the bus, the cable
length to each instrument must not exceed two meters (6.6 ft).
l
The total cable length between all instruments must not exceed 20 meters
(66 ft).
Hewlett-Packard manufactures HP-IB extender instruments (Models
HP
and HP that overcome the range limitations imposed by
the cabling rules. These extenders allow twin pair cable operation up to 1 km
(3,280 ft), and telephone modem operation over any distance. HP Sales and
Service Offices can provide additional information on the HP-IB extenders.
Table General Bus Management lines
Remote Enable R E N
End Or Identify
I
E O I
Controls whether bus is in Command Mode or Mode
FALSE].
Initializes the interface to an idle state activity on the bus).
Alerts the Controller to a need for communication.
Enables devices to respond to Remote Program Control when addressed
to listen.
Indicates last data byte of sequence; also used with ATN to parallel
poll devices for their status bit.
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