Comtech EF Data DT-4500 Series - Manual (Page 61)

DT4500 Series Down Converters MN/DT4500.IOM
Redundant System Operation Revision 1
43
R
EDUNDANT
C
ONFIGURATIONS
Comtech EF Data DT-4500 Series Down Converters can be configured in several
different redundant subsystem "Daisy Chain" configurations to meet the reliability
requirements of a communication system. These configurations include:
Table 13. 4500 Series Down Converter Configurations
1:1 Redundant Subsystems
Single Source IF Output Configuration
The online converter uses an IF transfer switch to switch the IF signal. A single
switched IF output is provided to and from the online converter. The transfer
switches are contained in the Receive Switch Module (RSM) installed in the online
converter. When a fault occurs in the online converter, the RSM is de-activated to
switch out the online converter, and switch the IF output to the backup Converter.
Figure 21 is an illustration of the cable connections between the converters.
Figure 22 is a block diagram of this 1:1 redundant converter configuration.
Dual Source IF Output Configuration
Two IF outputs, IF output #1 (priority) and IF output #2, are switched in the
Receive Switch Module (RSM) to provide redundant operation of the converters.
The converters provide two switched IF outputs, IF output #1 (priority) and IF
output #2. If converter #1 faults, converter #2 backs up the priority channel and IF
signal #2 is not operational. Figure 25 is an illustration of the cable connections
between the converters. Figure 26 is a block diagram of the 1:1 redundant, dual
source RF input, converter configuration.
1:N Redundant Subsystems
An IF switch in the RSM is used to switch the IF output of a faulted online
converter to the backup Converter. Figure 27 is an illustration of the cable
connections between the converters.
Figure 28 is a block diagram of this 1:N redundant "Daisy Chain" converter
configuration.