Chapter
4
41
Installing the PLC2/DHII Interface
This chapter presents procedures for:
Planning the Layout
Mounting the PLC-2/DHII Interface
Setting Switches
Connecting Communication Cables
Connecting Power
Read this chapter before you install the KP2 interface module. We
provide steps for you to follow for proper installation. Failure to follow
the steps provided may result in equipment damage.
The maximum distance between components is limited by cable length.
You must plan the layout so that the PLC-2/DHII interface is within
10 cable-feet of the PLC-2 family processor.
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 (PLC-2/DHII 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 PLC-2/DHII interface, the processor chassis, and
I/O chassis, but also the user-supplied power dissipated through the input
and output circuits.
Chapter Objectives
Planning the Layout
