Operational Network Specification - Comtech EF Data DMD50 Installation And Operation Manual

DMD50 Universal Satellite Modem
•
It contributes to the Terrestrial Framing Mode selection process. Trying to select a T1-type
Drop Mode such as T1-ESF with the mod data rate set to 1920000 bps (a valid E1 D&I rate
but not a valid T1 rate) will result in the error message 'INVALID DROP MODE' and the
selection will not be allowed. Trying to select a T1 type Insert Mode such as T1-D4 with the
demod data rate set to 1920000 bps will result in the error message INVALID INSERT
MODE and the selection will not be allowed.
•
Once D&I Mode has been selected, trying to change the data rate to something other than
another valid D&I data rate will result in the error message 'RATE OUT OF BOUNDS' and
the change will not be allowed.
•
Once D&I Mode has been selected with a T1 Terrestrial Framing Mode, attempting to
change the data rate to 1920000 will result in the error message 'RATE OUT OF BOUNDS'
and the change will not be allowed.
Therefore, the data rate should be entered as the first step in configuring the modem for D&I.
The Mod Data Rate should be set according to the number of timeslots to be dropped and the
Demod Data Rate should be set according to the number of timeslots to be inserted. The
following table gives the allowable D&I data rates based on the number of slots (n) to be dropped
or inserted.
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)
H.2.2 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 Specification of the modem is set to D&I. Therefore, the second step in configuring
the modem should be to set the Network Specification 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
Specification of the modem is changed to something other than D&I.
When the Network Specification is changed to something other than D&I, the D&I specific
menus will automatically disappear.
MN-DMD50– Revision 3
Drop and Insert (D&I)
H–9