46 097-55501-01 Issue 6 – June 2003
1
TimeHub 5500 System Guide
1.7 Expansion Shelf Capabilities
For situations requiring more outputs than can be provided by a master shelf,
the TimeHub 5500 supports an expansion shelf capability. Each expansion shelf
provides up to a maximum of 320 protected inputs. Up to four expansion shelves
can be added to a master shelf for a total possible protected output capacity of
1420 outputs per TimeHub system.
1.7.1 Functions Associated with Expansion Shelf Front
Side
Figure 1-5 shows the front side of the expansion shelf. There are two types
of plug-in cards used with an expansion shelf: output driver cards (p/n 090-
55581-01) and expansion controller cards (p/n 090-55545-01).
1.7.2 Output Driver Card (090-55581-01)
These are the same cards used on the master shelf. They can be used
interchangeably in either a master or expansion shelf (see note). Each card
provides 40 outputs, which can be provisioned as all DS1, all CC, or 20
outputs of each type. The front-panel LEDs indicate the actual provisioning.
The provisioning is determined by the configuration of output connector
modules on the rear of the expansion shelf (see Expansion Output
Connector Modules).
By pairing output driver cards a redundant protection scheme is achieved.
The cards work together such that if either card experiences a failure the
output integrity will be maintained. When cards are paired, insertion or
removal of either card has negligible impact on output timing or signal
integrity. Each protection pair supports 40 outputs. As indicated on the
expansion shelf panel, the protection groups are labeled "A", "B", …, "H". For
example, to protect the "B" group of 40 ports, output driver cards are
inserted into the two slots associated with "B".
N
OTE
: In order to support expansion shelves, the master shelf
should be equipped with extended capacity clock cards (090-
55512-02 and/or 090-55514-02). Standard clock cards (090-
55511-01 and/or 090-55513-01) do not support expansion
shelves. If your system has standard clock cards, you first have
to upgrade to extended capacity clock cards before using
expansion shelves.