Appendix A. Redundant System Operation; Redundancy Overview - Comtech EF Data DT-4572 Installation And Operation Manual

Appendix A. REDUNDANT
A.1 Redundancy Overview
Use of the word "converter" throughout this appendix applies to either
the Comtech EF Data DT-4572 X-Band Down Converter or the UT-4579
X-Band Up Converter.
The Comtech EF Data DT-4572 X-Band Down Converter functions in a redundant
system using distributed protection switching in an active "Daisy Chain"
configuration. This proprietary configuration distributes the converter protection
switching functions in the converters. This provides a system capability to back
up from 1 to 12 online converters.
A High Speed Bus (HSB) provides the communications interface between the
backup and online converters. The HSB detects faults and reconfigures the
subsystem to replace the failed converter. When a faulted converter is removed
from active operation, it detaches from the active converter chain by separating
the converter from its switch module. This leaves the active online converter
chain intact via the switch module. You can expand the chain without affecting
online converter operation.
You may also indirectly control the active chained converters in a redundancy
subsystem through the backup converter (BU) via the remote serial
communication link – see Chapter 8. SERIAL INTERFACE OPERATION for more
information.
SYSTEM OPERATION
A–1