User's Manual

Spread Spectrum Radio System User’s Manual 5
March 2001
The Hub is installed inside the equipment’s cab usually mounted to
the wall or on an upright bracket attached to the floor or rear dash. It
consists of a rugged case and base plate made of cast aluminum, which
has been anodized and enameled to provide maximum protection from
harsh environments. Its physical dimensions are approximately 35.4
by 26.2 by 9.4 centimeters (14 by 10.3 by 3.7 inches), and it weighs 4.3
kilograms (9.5 pounds).
Major Circuit Boards
The mobile equipment Hub houses the following major components:
• processor board
This board has an Intel SA1100 processor, DRAM, ROM, flash
memory, FPGA, Ethernet controller (10Base-T), CAN
controller, and other primary components. All transceivers and
isolation components are on the isolation interface board,
thereby making the processor board relatively stable. This
board is also small enough to allow full-size high-precision GPS
receivers to be mounted next to it inside the Hub cover.
• power board
This board distributes protected, isolated, and regulated power
to the system components. The input power source is nominally
12 or 24 V dc. The optional 12-V Hub has an operational range
of 10 to 19 volts; the optional 24-V Hub has an operational
range of 18 to 35 volts.
• connector board
This board provides the internal connections between the
power and isolation interface boards, and all connections to
external devices.
• isolation interface board
This board provides electrical protection and isolation to
signals coming from outside the Hub to the processor.
• location system (GPS) adapter board
This board provides the interface between the processor board
and the GPS receiver.