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DMD1050 Satellite Modem Board
3.16
Enhanced Asynchronous Mode (Radyne Proprietary)
Since many of the frame bits in the standard IBS mode are not used, an "Enhanced" Multiplexer
Mode has been implemented that can be engaged under software control. Since this mode
changes the use of many of the framed non-data bits, this mode is only usable when the
DMD1050 is at both ends of a link. In this mode, the overhead signaling bytes 16 and 48 can be
used to implement a significantly higher speed ES to ES Data Channel under software control.
When implemented, this rate is 16 times that of the normal ES to ES IBS mode, or 1/30
terrestrial data rate (1/32
The IBS 1/15 framing mode MUST be selected for Asynchronous channel
operation to be available.
IMPORTANT
3.17 Satellite Control Channel (SCC) - J1
The SCC format uses a variable overhead rate to transmit an asynchronous data channel in
addition to the normal data channel. The SCC asynchronous mode implemented on the DMD20
is "PassThru" Mode.
In Pass Thru Mode, there is no formatting or deformatting of the input data in the buffer, and it is
transmitted on a first-in first-out basis. In band data entering the remote port is inserted into the
user data stream. The in-band data is received and passed on to the user without any deformatting
or depacketizing involved. The maximum in band rate supported is 115200bps.
The Asynchronous Data Interface (J1) is a 10-Pin Dual Row header. The data interface can be
configured for RS232 or RS485 via the Web Browser or Terminal Screen. Refer to Table 4.3.4
for pinouts.
MN-DMD1050
Revision 9
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of the aggregate rate).
Theory of Operation
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of the
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