Network Card User Manual

Dial Shelf Field-Replaceable Units
Cisco AS5800 Universal Access Server Hardware Installation Guide1-24
Table 1-5 Dial Shelf Controller Card Front Panel Ports
Common Logic Interface
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 interface
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 connector on the dial
shelf controller card front panel.
Only one common logic is active at a time, identified by the CLK LED on the DSC card front panel.
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 controller card becomes the master,
clocking remains stable. The selected common logic should not be changed during normal operation
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, which 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. The PEMs provide power redundancy and
load-sharing; however, a single PEM can power 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 module are cooled by system air flow, which flows from the top to the back
of the dial shelf chassis. The front and sides of the PEMs are perforated 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 uninterrupted system
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.