Marconi Instruments 2955 - Page 23

INSTALLATION
GPIB
connector
contacts
The
contacts
on
the
GPIB cable
connector
and the device
connector
is
as shown
in
Fig-
2-2
below.
OfO
5
OlO
6
DIO
7
OlO 8
REN
FORMS TWISTHD PAIR
WITH
6
FORMS
TWISTED PAIR
WlYH
7
FORMS TWISTED
PAIR WITH
3
-FORMS TWISTED
PAJR
WITH 9
FORMS TWISTED
PAIR WITH
10
FORMS TWISTED
PAIR WITH 1
1
LOGIC
Earth
Fig, 2-2
GPIB
connector contacts
The
cables
have
special
male-female
connectors at both ends.
This
allows several
connectors
to
be
stacked
one
on top
of
another
permitting several cables
to be connected
to
the
same
source
and
secured
by a
lockscrew
mechanism.
Too
large a
stack
however,
may form
a
centilevered
structure
which
might
cause damage and should
be
avoided. The
piggyback
arrangement
permits
star
or
linear interconnection
between
the
devices
forming
a
system with
the
restriction
that
the
total
cable
length for
the
system
is
as
follows:
-
(1)
-Mo
greater
than
20
m
(65
ft).
(2)
No
greater
than
2 m
(6
ft)
times
the total number
of
devices
(including the
controller)
connected
to the
bus.
ACCESSORY
SOCKET
The
contact
numbering
of the 7-way
DIN socket
is
shown
in Fig.
2-3.
Reading
clockwise
from
the
earth
shield
locating
spigot,
the
functions
in
position
order
are
as
foilows;-
Position
Pin
Function
1
2
3
4
5
6
7
6
Logic
1 Logic
4
Forward
power
2
+12
V
DC
at approx
100
mA
5
Reverse
power
3
Logic
7
Demodulated
output
46881
-622N
Apr. 88 2-5