Cisco Systems AS5800 Dial Shelf DC-Input Power Supply

Dial Shelf Field-Replaceable Units

Cisco AS5800 Universal Access Server Hardware Installation Guide1-24

Table1-5 Dial Shelf Controller Card Front Panel Ports

Each DSC card contains a block of logic referred to as the common logic and system clocks. This

block generates the backplane Stratum-4 compliant 4-MHz and 8-kHz clocks used for interfac e

timing and for the TDM bus data movement. The common logic can use a variety of sources to

generate this system timing, including an E1 or T1 signal input from the BNC connect or on the dia l

shelf controller card front panel.

Only one common logic is active at a time, ident if ied b y t he CLK LED on t he DSC c ard fron t pa nel.

The active common logic is user-selectable and is independent from each DSC card. This assures

that if you need to replace a DSC, or if the slave dial shelf controlle r card becomes the master,

clocking remains stable. The selected common logic should n ot be change d during nor mal operatio n

unless a hardware failure is suspected or diagnosed in the DSC card.

Dial Shelf DC-Input Power Supply

The Cisco AS5800 is equipped with two power-entry modules (PEMs) in the dial shelf, whic h accept

DC-input power either from your site DC source or from an optional AC-input power shelf, and

distribute –48 VDC power to the dial shelf components . T he PEMs provide power redundancy and

load-sharing; however, a single PEM can powe r a fully configured system.

Note Whenever possible, we recommend that you connect each PEM to a separate DC power

source.

The PEMs and the filter mod ule ar e coo led by sys tem ai r f lo w, which flows from the t op to t he b ac k

of the dial shelf chassis. The front and sides of the PEMs are perf o rated for minimum air flow

restriction.

The PEMs support the following functions:

•Power redundancy and load sharing

The DC-input power supply provides redundant power by design. During normal operation, the

two PEMs provide system power simultaneously (load share ) . When you remove one PEM, the

remaining PEM immediately ramps up to provide full power and maintain uninter rupted s ystem

power.

Port Description

Console Provides RJ-45 connection to the system controller

console port for system management.

Network clock Provides BNC connection for an external T1 or E1

reference input signal from which a clock is extracted.

Alarms Provides DB-15 serial connection to an external audio

or visual alarm source .

10BaseT For Cisco internal use only.

Dial shelf interconnect Provides RJ-45 cable connection to the router shelf.