IBM Series 1 User Manual page 179

INTEGRATED DIGITAL I/O DESIGN CONSIDEB1TIOlfS
The integrated digital I/O points are all nonisolated. The
ground reference for all input and output points is the
top-card connector of the tea"ture card. User-supplied
cables that are appropriate to
the
environment should
be
used and, in most cases_ should
be
shielded. The shield
should be attached to frame ground as
it
enters
the
processor unit, the I/O expansion unit, or the 4997
enclosure. whichever comes first. There are grounds
provided for the reference half of each signal pair on the
top-card connector or the connector for the customer access
panel feature.
These grounds should be connected to frame
ground through a low impedance path.
The performance of this interface may
be
affected
by
noise. Appropriate arc suppression, noise filtering, etc.,
may
be
necessary on the user's inputs.
The cables that plug into the top-card connector on the
integrated digital I/O feature card should be made using #24
AiG wire and
must use Berg1 part number 75598-003 pins
(or
equivalent) and Berg part number 65405-013 housing (or
equivalent). Refer to Figure 5-6 for an illustration of the
cable connector.
The cable to the customer access panel can be made
using a
160-pin
male connector block, Amp2 part number
20799-2 (or equivalent); male contacts, Allp part number
66106-1
(or equivalent); and #24 AWG wire.
1Berg Electronics, Division of E.I. duPont de Nemours, Co.
2Amp, Incorporated
5-22 GA34-0033
f
~
'-
"