Comtech EF Data OM20 - Manual (Page 190)

OM20 Universal Outdoor Modem Appendix E
MN-OM20– Revision 5 E–8
n = 1, data rate = 64000
n = 2, data rate = 128000
n = 3, data rate = 192000
n = 4, data rate = 256000
n = 5, data rate = 320000
n = 6, data rate = 384000
n = 8, data rate = 512000
n = 10, data rate = 640000
n = 12, data rate = 768000
n = 15, data rate = 960000
n = 16, data rate = 1024000
n = 20, data rate = 1280000
n = 24, data rate = 1536000
n = 30, data rate = 1920000 (valid with E1 Interface only)
E.7.2 Operational Network Specification
The Network Specification of the Modem often determines which additional menus and displays
are available for use by the operator. The D&I Mode-specific menus will not be displayed unless
the Network Spec. of the modem is set to D&I. Therefore, the next step in configuring the
modem should be to set the Network Spec. to D&I. At this point, the D&I specific menus in the
Interface section will become available and will remain available until the Network Spec. of the
modem is changed to something other than D&I. When the Network Spec. is changed to
something other than D&I, the D&I specific menus will automatically disappear.
E.7.3 Terrestrial Framing - Drop Mode/Insert Mode
The Drop Mode Selection and the Insert Mode Selection identify the Terrestrial Data-Framing
Format. As previously mentioned, their selection is influenced by the Modulator and
Demodulator Data Rates, and trying to select a T1 Type Framing Format with a data rate of
1920000 bps will result in an error message. In turn, the selection of the terrestrial framing
formats influences the satellite channel to terrestrial timeslot mappings in the following manner:
The selection of T1-D4, T1-ESF, or SLC-96 type terrestrial framing format limits the
terrestrial timeslots to values from 1 - 24.
The selection of PCM-30 or PCM-30C type terrestrial framing limits the terrestrial timeslots
to values from 1 - 15, 17 - 31. In these modes, terrestrial timeslot 16 is reserved for ABCD
signaling and may not be dropped or inserted.
The selection of PCM-31 or PCM-31C type terrestrial framing limits the terrestrial timeslots
to values from 1 - 31. Therefore, the terrestrial framing format should be identified via the
Drop Mode and Insert Mode entries prior to editing the Drop or Insert satellite channel to
terrestrial timeslot maps.