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DMD50 Universal Satellite Modem
H.3
D&I Maps and Map Editing
The Drop and Insert multiplexer is programmed by loading it with a transmit and receive map.
Maps always contain 30 entries, although, only the first "n" entries are relevant (see Table 4-5).
The modem includes provisions to copy, change, and store the D&I transmit and receive maps
directly from the Front Panel or via the remote M&C link. These maps are tables that are used to
define and configure the D&I functions. Each map contains up to 30 entries, which are enough to
define the channel assignments for a T1 (24 channel) or E1 (30 channel) frame structure. Maps
that are created are stored in non-volatile battery backed-up memory within the modem and
remain unchanged after a power-down.
Data Rate (Kbps) Map Locations Used (n = 1, 2,4,8,16,24,30)
It is important to understand that each map contains up to 30 usable entries. In many cases a
smaller number of entries will be relevant, except when the data rate is 1920 Kbps, in which case
30 entries will used by the multiplexer. To determine the number of relevant entries, divide the
data rate by 64 Kbps.
For example:
Therefore, in this case only the first six entries of the map would be relevant.
MN-DMD50 Revision 4
Figure H-10. Rx Only No Trunk
Table H-1. D&I Multiplexer Map Locations Used
D&I Multiplexer Map Locations Used
64
128
256
384
512
768
1024
1536
1920
At 384 Kbps, 384/64 = 6 entries.
1
1-2
1-4
1-6
1-8
1-12
1-16
1-24
1-30
Drop and Insert (D&I)
H–13
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