COBHAM Sea Tel 2400, Руководство по установке

Страница: 14 / 120

Introduction Sea Tel 2400 Dual Band C/Ku
2-2
EAR Controlled - ECCN EAR99
2.5. Dual Antenna Configuration
Sometimes, due to very large blockage conditions, you may need to install a dual antenna configuration to provide
uninterrupted services. Two full antenna systems are installed and the MXP control outputs are connected to an
arbitrator switch panel which then is connected to the below decks equipment. NOTE: The RXIF from EACH
antenna MUST be connected to the RF IN on the rear panel of its respective MXP then RFOUT is connected to the
RXIF input of the Dual Antenna Arbitrator. This connection scheme is required for MXP “A” to be able to control
Antenna “A” (and ONLY Antenna “A”) AND MXP “B” to be able to control Antenna “B” (and ONLY Antenna “B”).
You will program the blockage zone(s) for each of the two antennas (refer to Setup – Blockage Zones). The
blockage output from the each of the MXPs is connected to the arbitrator panel to control it. The blockage output
terminal of each MXP provides a “blocked” output to the arbitrator its respective antenna is within a blockage zone
programmed into that MXP. When not blocked the SW2 terminal output(s) will signal an “unblocked” state..
When one antenna is blocked, its blockage output will command the arbitrator panel to switch services to 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 if the antenna to be repeatedly blocked – unblocked
– blocked.
2.6. Dual Network Arbitrator
Demand for greater bandwidth throughputs has led to service offerings that include access to multiple networks
from the vessel. To facilitate this a dual network (two modems) configuration is required.
This can be a single antenna – dual network configuration which allows the ship to access either of two networks.
One antenna system is installed and its’ ACU control output is connected to a dual network arbitrator switch panel
which is also connected to two satellite modems, and other below decks equipment if provided.
A dual antenna – dual network configuration allows the ship to access to two networks simultaneously. Two full
antenna systems are installed and the two ACU control outputs are connected to a dual network arbitrator switch
panel which is also connected to two satellite modems, 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.
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 ACUs and the Satellite Modem(s):
•
TX IF signal to the selected antenna from the selected Satellite Modem. 10 MHz reference is also passed
when provided by the modem.
•
RX IF from the selected antenna to the selected Satellite Modem.
•
Blockage control output from each ACU provides status of the antenna (available or blocked) to the
arbitrator.
•
GPS position - output from each antenna to the arbitrator. A setting in the in the arbitrator determines
which GPS signal gets routed to the satellite modem(s).
•
Receive Lock signal from the selected Satellite Modem(s) is routed to both ACUs to enable each of the
antennas to track the appropriate satellite/beam.
In single network mode, when one antenna is blocked, its blockage output will command the arbitrator panel to
switch services 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.
In dual network mode, if one antenna becomes blocked there is no available antenna to switch to, so that network
will be out of service until the antenna is no longer blocked.
2.7. 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 modems include
commands which allow remotely setting all of the necessary parameters and to command the targeting of the
desired satellite