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097-55501-01 Revision M – January 2009
TimeHub 5500 User’s Guide
67
Chapter 2 Engineering Ordering Information
Card Overview
Expansion Controller Card
The Expansion Controller card (090-55545-01) is only used in the Expansion shelf.
At least one Expansion Controller (EC) card is required for the Expansion shelf to
function properly. An EC card can be inserted in the leftmost (EC1) or rightmost
(EC2) slot on the Expansion shelf (see
). The overall function of the EC
card is the same regardless of which of these locations are used. The reason to use
two EC cards in the shelf is entirely to support redundancy. If one card should fail,
the other will maintain proper operation.
The EC card provides the following functions:
Buffering of timing and framing signals sourced by Clock cards in the Master
shelf, and delivery of those signals to the Expansion shelf output cards.
Communication (bi-directional) between Master and Expansion shelves.
Expansion shelf power monitoring and alarm reporting
Redundancy management
Signal integrity monitoring
Front Panel Indicators
illustrates the front panel of the Expansion Controller card.