Comtech EF Data CLO-10 - Manual (Page 92)

CLO-10 Link Optimizer Revision 1
Redundant System Operation MN/CLO-10.IOM
A.4 Description of Operation
Ease of Connection: Because the redundancy switch controller resides within the CLO-10
Redundant Unit, cabling the redundancy system is remarkably simple. As shown in Chapter 4.
CABLES AND CONNECTIONS, this is accomplished using three (3) daisy-chained IF BNC
connections and a system-specific, Daisy Chain High Speed Bus (HSB) Cable.
The HSB interface serves several purposes:
• The Redundant Unit communicates with the Traffic Units via the HSB, along with
controlling all bridge and backup functions of each Traffic Unit.
• Control of each Traffic Unit is accomplished by controlling relays in the IOSMs of
the Traffic Units, via the HSB.
• The HSB does not interfere with the remote serial communication link access to any
of the Units in the chain.
Remote Operation: For user remote serial M&C communication connection to any Traffic Unit,
the user must connect only to the Redundant Unit. The Redundant Unit then passes all M&C
communications through to the appropriate Traffic Unit.
Functional Capability Requirement: Because the Redundant Unit may back up any Traffic
Unit, the Redundant Unit must be of the same or higher functional capability as the system’s
Traffic Units (i.e., FAST options).
Key Reliability Features: The CLO-10 Redundancy System incorporates the following key
reliability features:
• An IOSM can be completely removed from any Traffic Unit, with cables still
attached, without interrupting or affecting traffic, and
• An IOSM can be replaced without disturbing other Traffic circuits.
A.4.1 Bridge Mode Operation
A key feature of the CLO-10 Redundancy architecture is its ability to allow the Redundant Unit
to bridge, or mirror, a Traffic Unit. The Redundant Unit “learns” and stores each Traffic Unit’s
configuration, then configures itself to bridge the highest priority Traffic Unit’s configuration.
The Redundant Unit is able to detect faults and reconfigure itself to replace any faulted Traffic
Unit. Changes in any Traffic Unit – i.e., frequency, bandwidth, etc. – are detected by the
Redundant Unit and are immediately copied. Additionally, information is obtained automatically
by the Redundant Unit from newly added Traffic Units.
Bridge Mode allows incoming IF signals from the modem’s Tx IF and Downconverter IF to feed,
via two IF splitters on the bridged Traffic Unit’s IOSM, to both the online Traffic Unit #2 and the
Redundant Unit. These signals allow the Redundant Unit to operate under the exact same
conditions and configuration as the Traffic Unit that is being bridged. No external test equipment
is needed to determine the health of the Redundant Unit.
A–8