Dual-Base (Chain) Redundancy Operation; Figure 4-1. Dual-Base (Chain) Redundancy Operation - Comtech EF Data MBT-4000B Installation And Operation Manual

Multi-Band Transceiver System
Redundant Configuration
4.2 Dual Base (Chain) Redundancy Operation
Refer to Figure 4-1 of typical Dual Base (Chain) Redundancy configuration.
RF SWITCHES
SHOWN IN
POSITION
B
TX
REJECT
FILTER
RX
REJECT
FILTER
COMTECHEFDATA
Note: 1:2 splitters/combiners may be substituted for the L-Band Input/Output switches.
The two base units cooperate in monitoring the health of the two BUCs, two external amplifiers,
two LNBs, and each other. In case of a fault on an on-line BUC/amplifier or LNB, the base
containing the corresponding standby chain will automatically switch over to the standby chain
according to the following rules:
Step Procedures
1 In dual base (chain) redundancy operation, the redundancy is 'slot' based. The corresponding
pairs reside in the same 'slot' of the opposite MBT-4000B base, the pair of BUCs connected to
J3 UNIT 1 COMM (slot 1) on each base form a redundant pair. The LNBs connected to
"L BAND IN" on each base form the other redundant pair.
2 The corresponding BUCs in a pair must be of the same type.
3 The redundancy interlink cable (P/N: CA/WR11224-1 or equivalent), must be installed.
4 Base unit identification (MBT A or MBT B) is driven by the redundancy interlink cable. Hard-
wired connections within the cable designate one MBT-4000B base as MBT-A and the other as
MBT-B. The cable is labeled accordingly.
5 The RF and IF switches connected to MBT-A correspond to the redundant pair of BUCs
installed on J3 UNIT 1 COMM (slot 1).
6 The RF and IF switches connected to MBT-B correspond to the redundant pair of LNBs
installed on the "L Band In" connectors.
7 When a BUC or LNB attached to MBT-A is on-line, the corresponding RF and IF switches will
be switched to position A. When a BUC or LNB attached to MBT-B is on-line, the
corresponding switches will be switched to position B.
LNB2
LNB1
SWITCH 2 RF
AUX COMM 1
WAVEGUIDE
SSPA 2
LOAD
SSPA 1
WAVEGUIDE
SWITCH 1 RF
Figure 4-1. Dual Base (Chain) Redundancy Operation
BIAST
1:1 MBT SUBSYSTEM
BUC 2 (Slot 1)
J10 J9 J7 J3
J5
UNIT 1
COMM
REDUNDANCY
INTERLINK CABLE
J7
BIAST
1:1 MBT SUBSYSTEM
BUC 1 (Slot 1)
J10 J9 J3
UNIT 1
COMM
AUX COMM 1
4-2
MN/MBT4000B.IOM
LOAD
RX
SWITCH 2 IF
L-BAND
MODEM
TX
LOAD
J5 SWITCH 1 IF
DUAL MBT-4000 REDUNDANT SWITCH
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