IBUC Operation Manual
Terrasat Communications, Inc.
Rev. A
7-1
Chapter 7 IBUC Redundant Systems
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Introduction
The IBUC can be installed and configured as a redundant system providing automatic
switching to a standby unit in the event of failure of an online unit. A companion
receive redundant system is also available for protection of LNBs. The receive
redundant system has a separate interface controller but shares the DC power supplies
used by the transmit redundant system IBUC’s. The power supply for Redundant
Systems is available in two versions: indoor rack-mount and outdoor types. The 200W
hot-swappable dual Power Supply (indoor rack-mount) is housed in a Standard 1RU
(19 inches rack) and powers Low Power Tx (up to 12W) and Rx Redundant Systems.
The outdoor PSUI’s come in a weatherproof housing and can power all of the Terrasat
Redundant Systems.
Description
Figure 7-1 is a diagram of a typical redundant system.
A redundant transmit system includes two IBUC’s of the same frequency band
connected to an interface box and an RF switch. An external power supply, PSUI-524,
PSUI-548 or PSUI-648, is required for each IBUC. Low power Redundant Systems can
also be powered by an indoor rack-mount Dual Power Supply, PSUI-1024 (24VDC) or
PSUI-1048 (48VDC). The IBUC’s, interface box, and RF switch are typically mounted
on a common mounting plate and connected with supplied cables and waveguide
components. The system provides automatic switching between IBUC’s in the event of
failure. The IBUC’s communicate with each other to monitor status and execute
switching logic. A software command is available in the IBUC to enable the unit
designated master, to clone itself to the slave to match the unit configuration. Monitor
and Control functions are available through the interface box via Hand Held terminal
(one connector for each IBUC), RS232 (one connector for each IBUC, same as HHT),
RS485 (user interface connector), TCP/IP (user interface connector), and FSK (coaxial
connection), as in the individual IBUC’s. In the redundant system, remote M&C via
RS485 and TCP/IP is done via the interface box which eliminates the need to run two
separate M&C cables to the IBUCs. In the case of FSK, M&C is available on the IFL
cable and no additional cable is required. M&C commands for redundancy systems are
already resident in the IBUC software (see Table 6-9, Chapter 6).
The receive redundancy system provides for switching of LNBs via a separate receive
interface box. Switching is accomplished using a waveguide switch that switches the RF
receive signal and a RF relay (internal to the Interface box) that switches the IF signal.
M&C is available via hand held terminal, RS232, RS485, and TCP/IP at the user
interface port on the RX interface box.
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