Instruction manual

Control Unit
Carriers
The carriers in the system are the containers that hold the modules on which the
circuit boards and connections for lines/trunks and extensions (called
jacks or
ports ) are. There can be up to three carriers: one basic carrier and two
expansion carriers.
The carriers hold the modules in slots. For the purposes of system programming
and installation, 2-digit numbers indicate the slots, starting with 00 for the
processor module.
Inside the back of each carrier is a component called the
backplane , which
holds the circuitry that makes it possible for the modules to “
talk
”
to each other
and for the processor module to handle the traffic among the modules.
Every system has a
basic carrier that holds the following modules in its slots:
■
Power supply module (not numbered)
■
Processor module (slot 00)
■
Up to five line/trunk and extension modules (slots 01–05)
If you need more trunks and/or extensions than can fit in the basic carrier, you
can connect up to two
expansion carriers to the basic carrier. Like the basic
carrier, each expansion carrier’s leftmost slot holds a power supply module; the
remaining six slots hold line/trunk and extension modules. (The processor
module in the basic carrier serves the expansion carriers too.) The six slots for
line/trunk and extension modules in the expansion carriers are numbered as
follows:
■
First expansion carrier: slots 06−11
■
Second expansion carrier: slots 12−17
Processor Module
The processor module is the “
brains
” of the system, a miniature computer that
controls system features and diagnostics, as well as the traffic among the
modules (see Figure 3−1). The processor module provides three jacks, one for
Station Message Detail Recording (labeled
SMDR ), one for system
programming and maintenance using a PC (labeled
ADMIN ), and one for
software maintenance by AT&T technicians only (this one is plugged shut).
The Personal Computer Memory Card International Association (PCMCIA)
interface slot on the processor module is the place in which you insert a
PCMCIA memory card. A memory card is very similar to a floppy diskette used
in a PC, but it is about the size of a credit card. There are different types of
memory cards used with the system, each with a different label; see the next
section for more information.
3–2 System Components