ViaSat ArcLight, Руководство пользователя, Страница: 284 / 368

ArcLight Hub User’s Guide
Component Operating Procedures
5-32 1081006 Rev. 001
5.10.2 Physical Interfaces
5.10.2.1 Serial Port Interfaces
The Serial Port signals are defined as listed in Table 5-2. There are 3
external serial ports (mini DB-9 connectors), 1 on each M&C and WAM
in the chassis.
Table 5-2. Serial Port Signal Description
Signal
No.
Signal
Name
Signal Function I/O Direction
(relative to FLM)
1 RXD Receive data I
2 TXD Transmit data O
3 GND Signal ground
In normal operation the M&C serial ports are not active as they are
used over the backplane for the UC configuration and monitoring. They
can be redirected for troubleshooting purposes if needed either on
startup or subsequently via Telnet.
5.10.2.2 Ethernet Interfaces
The MCD Ethernet interfaces are RJ-45 10/100 Base-T interfaces
complying with the physical and electrical characteristics of the IEEE
802.3 specification. The MCD has up to 4 ethernet interfaces (2 on each
M&C). The M&C front Ethernet interfaces are not used. Only the rear
interfaces are used.
5.10.2.3 RF Receive Interfaces
The MCD has the following Tx/Rx interfaces all on its rear panel:
•
Rx In 70-Mhz 75-Ohm BNC – usually connected to the
appropriate PCMAHC or the appropriate downconverter, e.g. L-
Band downconverter. A matching pad may be needed if the
other side of the connected cable has a 50-Ohm connector.
•
DVB In 70-Mhz 75-Ohm BNC – internally routed to the UC and
not used.
5.10.2.4 External Reference Interface
The MCD is provided a reference by the hub. This reference is
distributed to all of the hub components. The input reference
requirements to the MCD are listed in Table 5-12. Table 5-4 lists the
I/O chassis requirements for the ABS.