Symmetricom TimeHub 5500 User Manual

097-55501-01 Revision M – January 2009 TimeHub 5500 User’s Guide 41
Chapter 1 Description
Expansion Shelf
Figure 1-6. TimeHub 5500 Expansion Shelf – Front View
The Main shelf and the Expansion shelf are connected by two redundant expansion
cables. These cables provide the clock signals (Clock 1, Clock 2, and the
passthrough clock) to the Expansion shelf. The clock signals are in a proprietary
format running at 1.544 Mbps. The Expansion Controller cards are described in
Expansion Controller Card, on page 42.
Output Driver Cards
The Expansion shelf uses the same DS1/CC Driver cards used on the Master shelf
(see the following Note). Each DS1/CC Driver card provides 40 outputs, which can be
provisioned as all DS1, all Composite Clock (CC), or 20 outputs of each type. The
front-panel LEDs indicate the actual provisioning. The DS1 or CC Output Connector
modules installed on the rear panel of the Expansion shelf determine the type of
output signal.
The NTP Server card and the 5 MHz Output Driver cards can be used in the
Expansion shelf.
The Output Driver cards are paired to provide a redundant protection scheme. The
cards work together such that if either card experiences a failure the output integrity
is maintained. When cards are paired, inserting or removing either card has
negligible impact on output timing or signal integrity. The Expansion shelf supports
16 Output Driver cards, arranged in groups labeled “A”, “B”, …, “H”.

Symmetricom TimeHub 5500 Specifications

General

Brand	Symmetricom
Model	TimeHub 5500
Category	Data Loggers
Language	English