COBHAM Sea Tel Dual Antenna Arbitrator, Installation Manual

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Introduction Dual Antenna Arbitrator (MXP)
1-1
1. Introduction
The Dual Antenna Arbitrator is to be used with two complete Sea Tel Transmit/Receive (TX/RX) satellite communication
systems. The primary purpose of the Dual Antenna Arbitrator is to switch services from one antenna, which has become
blocked by the ships structure or has otherwise lost service, to the other antenna. Switching services to the satellite modem
under these conditions greatly improves on-air time by reducing the out of service time.
Additionally, this device allows for remote monitor, control and diagnostics directly or with Out of Band Management
(OBM) device(s).
1.1. Dual Antenna Configuration
Sometimes, due to very large blockage conditions, you may need to install a dual antenna configuration to provide
virtually uninterrupted services. Two full antenna systems are installed and the two ACU control outputs are
connected to a dual antenna arbitrator switch panel which then is connected to the satellite modem, and other
below decks equipment if provided. Refer to the appropriate installation chapter for the model of the Sea Tel
antenna systems that you will be installing this arbitrator panel with.
You will program the blockage zone(s) and optimize all other settings for best “on-satellite” performance for each
of the two Sea Tel antennas.
The following signals pass through the arbitrator to/from the ACU’s and the Satellite Modem:
•
TX IF signal to the active (selected) antenna from the Satellite Modem. 10 MHz reference is also passed
when provided by the modem.
•
RX IF from the active (selected) antenna to the Satellite Modem
•
Blockage control output from each ACU – this output provides signal to the arbitrator when the antenna
it is connected to is not available for services.
•
GPS position - output from the active (selected) antenna (this setting can be changed in the arbitrator).
•
Network Lock signal from the Satellite Modem is routed to both ACU’s to enable both antennas to track
the same satellite.
When one antenna is blocked, its blockage output will command the arbitrator panel to switch services for the
modem from that antenna to the other antenna. The arbitrator panel provides a logic latch to prevent excess
switching when the ship heading is yawing, therefore, causing either antenna to be repeatedly blocked –
unblocked – blocked.
1.2. Dual Antenna Arbitrator
The Dual Antenna Arbitrator panel automatically switches the signal from one of the two antennas. It can pass
LNB voltages (and handle 250-400 ma of current) and all of the typical RX IF and M&C signals on the RX
connections.
DC Voltage to power the BUC(s) should NOT be passed through this arbitrator panel, nor the dual channel coax
rotary joint of the antenna pedestal. BUC power should be supplied on the Antenna Pedestal.
TX IF and Reference signals can be passed through the dual antenna arbitrator.
The blockage (SW2) output, GPS output and Modem lock input from the two terminal mounting strips (antenna
“A” and antenna “B”) are wired through the arbitrator panel to the satellite modem. When antenna “A” is blocked,
the arbitrator PCB will toggle the coax switches so that antenna “B” provides signal to the satellite modem. When
antenna “A” is no longer blocked the arbitrator will do nothing (because it is a latch circuit). When antenna “B” is
blocked the panel will switch so that antenna “A” is again providing signal the BDE distribution.
To provide a seamless switching transition, refer to the arbitrator installation instructions to balance the TX & RX
signal levels between the two antennas.
1.3. Automatic Beam Switching (ABS)
ABS is a method of communicating remotely via an overhead channel, or locally from the modem, to reconfigure
the ACU(s) to use a different beam on the same satellite or to use a different satellite. The ACU’s include
commands which allow remotely setting all of the necessary parameters and to command the targeting of the
desired satellite.
1.4. OpenAMIP™
OpenAMIP
TM
is a standardized language incorporated into the current iDirect modems which communicates
automatic beam switching settings from the option file to the Sea Tel ACU(s). This allows the network to
accomplish to provide automatic beam switching remotely by switching option files in the remote modem.