Hp-Ib Connections And Interfacing; Cable Length Restrictions - HP 3585A Service Manual

Model 3585A
2·1 6. Hp·IB CONNECTIONS AND INTERFACING*
The 3585A HP-IB connector (Figure 2-5) is compatible with the -hp- 1 063 1 (A, B, C or D)
HP-IB Cables. The 3585A uses all of the HP-IB lines. The HP-IB system allows you to inter­
connect up to fourteen HP-IB compatible instruments (including the controller). The HP-IB
Cables have identical "piggyback" connectors on both ends so that several cables can be
connected to a single source without special adapters or switch boxes. You can interconnect
system components and devices in virtually any configuration you desire. There must, of
course, be a path from the calculator (or other controller) to every device operating on the
bus. As a practical matter, avoid stacking more than three or four cables on any one connec­
tor. If the stack gets too long, the force on the stack can produce sufficient leverage to
damage the connector mounting. Be sure that each connector is firmly screwed in place to
keep it from working loose (see CAUTION in Figure 2-5).
2 · 1 7 . Cable Length Restrictions
To achieve design performance with the HP-IB, proper voltage levels and timing relation­
ships must be maintained. If the system cables are too long, the lines cannot be driven pro­
perly and consequently, the system will fail to perform. When interconnecting an HP-IB
system, observe the following rules:
a. The total cable length for the system must be less than or equa i to 20 meters (65 feet).
b. The total cable length for the system must be less than or equa) to 2 meters (6 feet)
times the total number of devices connected to the bus.
L I N E
P I N
1 0 1 0 1
2 0 1 02
3
0 1 03
4 0 1 04
1 3 0 1 05
1 4 0 1 06
1 5 0 1 07
1 6 0 1 08
5 EOI
1 7 R E N
DAV
6
7 N R F D
NDAC
8
9 I F C
1 0 SRQ
1 1 ATN
1 2 SH I E L D-CHASS I S G ROUND
PlO TWISTED PA t R WITH P I N 6
1 8
1 9 PlO TWISTED PA I R WITH P I N 7
20 PlO TWISTED PA I R W I TH P I N 8
PlO TWISTED PA I R WITH PIN 9
21
PlO TWISTED PA I R WITH P I N 10
22
PlO TWISTED PAI R WITH P I N 1 1
23
24 ISOLATED D I G I TAL G ROUND
*Hewlett-Packard Interface Bus (HP-IB) is -hp-'s implementation of IEEE Standard 488- 1975, "Digital Inter­
face for Programmable Instrumentation" .
3585A
The
1 063 1 A, B,
studs as opposed to English threads. Metric threaded �hp�
secure the cable to the instrument. Identifica tion of the two
types o f mounting studs and lockscrews is made b y their
calor. English threaded fasteners are colored silver and
metric threaded fasteners are colored black. DO NO T mate
sliver and black fasteners to each other or the threads of
either or both will be destro yed. Metric threaded
cable hardware illustrations and part numbers follo w.
!
LOCKSCREW
1390-0360
THESE PINS
ARE
INTERN ALLY
GROUNDED
Figure 2·5. Hp·IB Connector
Installation and Interfacing
HP�/B
con tains me tric threaded cable moun ting
C HP�/B
or cable lockscrews must be used to
LONG MOUNTI NG STUO SHORT MOUNTING STUD
0380 -0643
HP�/B
0380-0644
2-9