Specifications Summary; Table A-21. Specification Summary - Comtech EF Data SDM-300A Installation And Operation Manual

SDM-300A Satellite Modem
A.3.3.2

Specifications Summary

Refer to Table A-21 and Table A-22 for specification summary and MUX data for
connector (J10).
Number of Channels
(Tributaries)
Tributary Type
Tributary Data Interface
Tributary Data Rate
Synchronous
Asynchronous
MUX Overhead
MUX Technique
Aggregate Data Rate
Tributary Data Interface
(Synchronous Mode)
Tributary Clock Output
(Synchronous Mode)
Tributary Data Interface
(Asynchronous Mode)
Receive Channel Pass Through
Interface Connector
Interface I/O Card (PC/6029)
Breakout Panel (UB-54)
Rev. 4

Table A-21. Specification Summary

System Specification
1 to 8, the data rate for each channel is independently configurable.
Synchronous (clock/data) or Asynchronous (data only).
EIA-422 or EIA-232-C, selectable per tributary.
Note: EIA-232-C maximum data rate is 64.0 kbit/s.
600 bit/s to 4000 kbit/s in 100 bit/s increments.
600 baud to 64k K-baud in 100 bit/s increments.
1.3 kbit/s, fixed.
Data Interleaved Time Division.
4001.3 kbit/s maximum, the aggregate data rate is the sum of all
tributary data rates plus the multiplex overhead.
MUX System Specification
The MUX supports a synchronous data interface for each tributary.
The tributary data interfaces use DCE conventions with data (send
data) sourced by external equipment and clock (send timing) sourced
by the MUX.
50% duty cycle ± 10%, clock (send timing) is phase locked to the
aggregate clock supplied by the modem. Clock stability is based on the
reference source. The clock accuracy will nominally be
10E-5 when using the modem SCT clock. Higher stability can be
obtained by using the modem External Reference input.
The MUX supports an asynchronous data interface for each tributary.
The tributary data interfaces use DCE conventions with data (send
data) sourced by external equipment. The MUX samples the input data
and passes it across the communications channel. All data formatting
and framing is preserved, including start/stop bits and parity.
Note: CTS (clear to send) flow control is employed to prevent loss of
data caused by clock differences between the asynchronous source and
the synchronous satellite channel.
The MUX provides an output path for the received clock/data from the
SDM-300A modem.
96-pin female DIN connector (includes all tributary interfaces).
96-pin male DIN to 100-pin subminiature D conversion PC card.
Optional 1 RU breakout panel converts 100-pin D interface to eight
15-pin D separate tributary interfaces and one 15-pin D connector for
auxiliary circuits.
Options
A–77