User's Manual Part 1

ADCP-75-187 Preliminary Issue 1B November 2005 Section 2: DESCRIPTION
Page 2-5
© 2005, ADC Telecommunications, Inc.
2.8 Controller Area Network Interface Connection
Controller Area Network (CAN) interface connections between multiple HUs are supported by
a pair of RJ-45 jacks. One of the jacks is designated as the network IN port and the other jack is
designated as the network OUT port. The CAN interface allows up to 24 HUs to be connected
together (in daisy-chain fashion) and controlled through a single EMS computer.
2.9 Service Interface Connection
The service interface connection between the HU and the EMS computer is supported by a
single DB-9 female connector. The service connector provides an RS-232 DTE interface. When
multiple HUs are networked together, the supporting EMS computer may be connected to the
service connector of any one of the networked HUs.
2.10 Powering
The HU is powered by ± 21 to ± 60 VDC power (nominal ± 24 or ± 48 VDC). The power is fed to
the HU through a screw-down type terminal strip located on the rear side of the unit. Power to
the HU must be supplied through a fuse panel such as the PowerWorx GMT Series Fuse Panel
(available separately). The power circuit for each HU must be protected with a 3 Amp GMT
fuse. An On/Off switch is provided on the HU front panel.
2.11 Cooling
Continuous airflow for cooling is provided by dual fans mounted on the right side of the HU
housing. A minimum of 3 inches (76 mm) of clearance space must be provided on both the left
and right sides of the HU for air intake and exhaust. An alarm is generated if a high temperature
condition (>50º C/122º F) occurs. The fans may be field-replaced if either fan fails.
2.12 User Interface
The HU user interface consists of the various connectors, switches, terminals, and LEDs that are
provided on the HU front and rear panels. The rear access HU user interface points are
indicated in Figure 2-2 and described in Table 2-1. The front access HU user interface points
are indicated in Figure 2-3 and described in Table 2-2.