Comtech EF Data DT-4500-A Series - Manual (Page 141)

B–1
Appendix B. REDUNDANT
SYSTEM OPERATION
B.1 Introduction to Redundancy Operation
The Comtech EF Data DT-4500-A Series Downconverters are configured for redundant system
operation using distributed protection switching in an active "Daisy Chain" configuration.
Comtech EF Data's proprietary "Daisy Chain" configuration distributes the downconverter
protection switching functions in the downconverters. This provides a system capability to
backup from 1 to 12 online downconverters.
A High Speed Bus (HSB) provides the communications interface between the backup and online
downconverters to detect faults and reconfigure the subsystem to replace the failed
downconverter. When a faulted downconverter is removed from active operation, it is detached
from the active downconverter chain by separating the downconverter from its switch module,
leaving the active online downconverter chain intact through the switch module. The chain can
be extended without affecting the online downconverter operation.
The active "chained" downconverters in a redundancy subsystem can also be indirectly
controlled through the backup downconverter using the remote serial communication link – this
capability is discussed in Appendix A. REMOTE CONTROL.