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Chapter
4
41
Installing the 1779KFM Interface
This chapter presents procedures for:
Planning the Layout
Mounting the 1779-KFM Interface
Setting Switches
Connecting Communication Cables
Connecting Power and Ground
The maximum distance between components is limited by cable length.
You must plan the layout so that the 1779-KFM interface is within
4,000 cable-feet of the host computer. The minimum component spacing
is limited by heat dissipation considerations.
The temperature of the air must not exceed 60
o
C (140
o
F) at any point
immediately below any chassis (1779-KFM interface, processor chassis,
I/O chassis, power supply). The failure rate of the semiconductor devices
may increase significantly if the temperature is raised above 60
o
C.
Furthermore, a significant decrease in the failure rate of the
semiconductor devices can be expected for every degree below 60
o
C that
the ambient temperature can be kept.
The temperature will tend to be higher toward the top of the enclosure.
Factors that determine the level at which the temperature will be 60
o
C
include:
The Size of the Enclosure
The Power Dissipation within the Enclosure
The Temperature of the Air Surrounding the Enclosure
Power dissipation includes not only the power dissipated through the
power supplies for the 1779-KFM interface, the processor chassis, and I/O
chassis but also the user-supplied power dissipated through input and
output circuits.
Chapter Objectives
Planning the Layout