Comtech EF Data OM20 User Manual
Page 57

OM20 Universal Outdoor Modem
OM20 Theory of Operation
MN-OM20– Revision 5
4–19
1536
768
576
9600
1664
832
640
19200
1792
896
704
19200
1920
960
768
19200
1920
960
768
19200
2048
1024
832
19200
896
19200
960
19200
1024
19200
1088
19200
1152
19200
1216
19200
1280
19200
1344
19200
1408
19200
1472
19200
1536
19200
1600
19200
1664
19200
1728
19200
1792
19200
1856
19200
1920
19200
1984
19200
2048
19200
4.13 Standard IBS Mode
In the first or “Normal” mode, all bit assignments are per the IBS standard. The bits of Overhead
Housekeeping byte 32 are implemented as shown in Table 4-3 below:
Table 4-3.
Bit 1
ES to ES Data
Channel
This bit is routed directly to the ES to ES Data Channel.
Its data rate is 1/512
th
of the aggregate rate (or 1/480
th
of
the through terrestrial data rate), and is normally used to
super-sample an asynchronous data channel.