Specifications

Rev. 0 B–1
Appendix B.
OPTIONS
This appendix provides information about the following options:
• Asynchronous/Automatic Uplink Power Control (AUPC Interface)
• ADPCM Voice Interface
• Reed-Solomon Codec
B.1 AUPC Interface
The asynchronous (ASYNC) interface board provides the interface for terrestrial data and
a single ASYNC overhead channel.
Refer to Figure B-1 for a modem block diagram with the ASYNC/AUPC interface
option.
RS-422 or V.35 interfaces are also available for terrestrial data input and output. These
interfaces can be selected via the front panel.
RS-485 or RS-232-C interfaces are available for ASYNC channel input and output.
These interfaces can also be selected from the front panel. Fixed 1/16 overhead is added
to the data when an ASYNC channel is being used. With the ASYNC channel enabled,
the terrestrial date rate can be from 9.6 to 224 kbit/s. The ASYNC channel I/O protocol
can be as follows:
Baud 150 to 2400
Data bits 5 to 8
Parity Odd, even, or none
Stop bits 1 or 2
Note: Certain combinations of baud rate, data rate, parity, and stop bits will limit the
maximum baud rate allowed for continuous throughput based on terrestrial data rate.