OM20 Universal Outdoor Modem
OM20 Theory of Operation
MN-OM20– Revision 5
4–20
Bit 2
Frame Alignment
Part of the Frame Alignment word.
Bit 3
Backward Alarm
Transmit and Receive with main processor to activate
Main Alarm/LED.
Bit 4
Multiframe Message
As per IBS.
Bits 5 and 6
Spare
Not currently utilized.
Bits 7 and 8
Encryption
Utilization
Not currently utilized.
The ratio of the Through Terrestrial Data Channel Rate to the aggregate rate is 15/16. The
standard transmit and receive channels of the ES to ES Data Channel in Standard IBS Mode are
raw channels operating at the specific bit rate as controlled by the data channel rate, without
buffering. In addition, no clocks are provided with this channel. Since it would be rare that the
data rate provided was exactly that required for a standard rate device, the only method of
communicating using this channel is to allow it to super-sample the user data.
4.14
Asynchronous Multiplexer Mode
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 modem 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 IBS standard, or 1/30
th
of the terrestrial data rate (1/32
nd
of the aggregate
rate).
Summary of Contents for OM20
Page 2: ......
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Page 20: ...OM20 Universal Outdoor Modem Introduction MN OM20 Revision 5 1 4 Notes ...
Page 32: ...OM20 Universal Outdoor Modem Installation MN OM20 Revision 5 2 12 Notes ...
Page 38: ...OM20 Universal Outdoor Modem OM20 Initial Configuration MN OM20 Revision 5 3 6 Notes ...
Page 66: ...OM20 Universal Outdoor Modem OM20 Theory of Operation MN OM20 Revision 5 4 28 Notes ...
Page 138: ...OM20 Universal Outdoor Modem Web Browser Remote Protocol MN OM20 Revision 5 6 64 ...
Page 164: ...OM20 Universal Outdoor Modem Technical Specifications MN OM20 Revision 5 8 20 Notes ...
Page 198: ...OM20 Universal Outdoor Modem Appendix E MN OM20 Revision 5 E 16 Notes ...
Page 204: ...OM20 Universal Outdoor Modem Appendix F MN OM20 Revision 5 F 6 Notes ...
Page 214: ...OM20 Universal Outdoor Modem Appendix G MN OM20 Revision 5 G 10 Notes ...
Page 218: ...OM20 Universal Outdoor Modem Appendix G MN OM20 Revision 5 H 4 Notes ...
Page 220: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX ...