SmartEdge 600 Router Hardware Guide
6.1.2.3
NVRAM with Battery
The NVRAM battery on the XCRP4 Controller card is rechargeable; it is
recharged from the power supplied to the SmartEdge router during normal
operations. The battery typically lasts more than two years when fully charged
and without benefit of being recharged by being powered on.
6.1.2.4
System Clock
The internal clock on an XCRP4 Controller card is a SONET minimum clock
(SMC) at ±20.0 ppm in free-run and normal modes only. The system clock
performs timing functions for system hardware, regardless of the source of its
timing data. Using the SmartEdge OS, you can specify external equipment
(external timing mode), the received clock of a line card (line timing mode), or
the internal clock on the controller card (internal mode) as the source for the
system clock. The real-time clock (RTC) on the XCRP4 Controller cards is
initialized before the system is shipped. It is not affected by power failures,
system shutdown, or reload. The RTC uses the NVRAM battery. By default,
the source of the transmit clock for the ports on a line card is its onboard clock.
Depending on the type of line card, the transmit clock for a port on a line card
can use instead the receive clock derived from an incoming signal to the port or
system clock. Because a port does not interface to the source of the system
clock directly, line card synchronization is independent of the type of external
timing equipment and the version of the controller card installed in the chassis.
6.1.2.5
External Timing Connection
Figure 35
External Timing Cables Connections
An external timing cable provides a connection from an external synchronization
source, such as a building integrated timing supply (BITS) or synchronization
supply unit (SSU), to the SmartEdge router. Each cable consists of two
individually shielded, twisted wire pairs: one pair for the synchronization input
and another pair for the synchronization output.
Note:
For the XCRP4 Controller card, the type of interface is software
selectable. The SmartEdge OS does not support transmission of data
to another SmartEdge router or any other external equipment.
112
27/153 30-CRA 119 1170/1 Uen A
|
2010-04-09
Summary of Contents for SmartEdge 600
Page 1: ...SmartEdge 600 Router Hardware Guide Release 6 3 INSTALLATION 27 153 30 CRA 119 1170 1 Uen A ...
Page 6: ...SmartEdge 600 Router Hardware Guide 27 153 30 CRA 119 1170 1 Uen A 2010 04 09 ...
Page 26: ...SmartEdge 600 Router Hardware Guide 20 27 153 30 CRA 119 1170 1 Uen A 2010 04 09 ...
Page 108: ...SmartEdge 600 Router Hardware Guide 102 27 153 30 CRA 119 1170 1 Uen A 2010 04 09 ...
Page 112: ...SmartEdge 600 Router Hardware Guide 106 27 153 30 CRA 119 1170 1 Uen A 2010 04 09 ...
