Comtech EF Data DMD-2050E Installation And Operation Manual page 300

DMD2050E Universal Satellite Modem
map through the modem's LCD; when editing is complete, the appropriate map should be copied
to the Active Map.
Any map may be copied to any other map with the exception of the ROM maps. These maps
may only be the source of the data used to create a User, Edit, or Active Map.
Maps can be created in the map editor and stored as "User Maps". New "Active Maps" can be
downloaded during Modem Operation but this will result in a temporary disruption of service on
the terrestrial line or the Satellite transmission.
The following paragraphs give examples of typical configurations that could use the ROM Maps
as templates. The ROM Map used would have to be first copied to the appropriate Active
Transmit (Drop) and/or Active Receive (Insert) Map(s) before it could be used. To use a
modification of a ROM Map, the ROM Map must first be copied to the appropriate Edit Map, then
modified, and then copied to the appropriate Active Map.
IMPORTANT
The mapping of channels to time slots is arbitrary; it is not necessary to map CH1 to
TS1, CH2 to TS2, etc. The channel to the time slot mapping may be in any order
within the constraints of the number of available channels.
For example, ROM Map 1 could be used as the template for an Active Transmit (Drop) Map
within a modulator configured for 64 Kbps operation. Only the first time slot of the T1 or E1 frame
would be dropped into the modulator transmit path. The Drop Multiplexer would know to look
only at the first entry in the Active Transmit table and would ignore the other 29 entries. If the
map contained an "8" in its first entry, the eighth channel of the T1/E1 frame would be sent to the
modulator.
ROM Map 2 could be used as the template for an Active Receive (Insert) Map within a
demodulator configured for 128 Kbps operation. The demodulated data in the receive path would
be inserted into the first two time slots of the T1 or E1 frame. The Insert Multiplexer would know
to look only at the first two entries in the Active Receive table and would ignore the other 28
entries. If the first two entries were modified to contain a 27 and 28, the data would be inserted
into the 27 and 28
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ROM Map 3 could be used as the template for an Active Transmit (Drop) Map with a modulator
and/or demodulator configured for 256 Kbps operation. The T1 or E1 Data in the transmit path or
the demodulated data in the receive path would be dropped from and/or inserted into the first four
MN-DMD2050E Revision 2
time slots of the E1 frame.
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Efficient Drop and Insert
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