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CDM-710G High-Speed Satellite Modem
HSSI Interface (CDI-60)
13.4
General Specifications
Item
Data Rate Range
Interfaces Per Module
Signals Supported
Connector
Electrical
Electrical Typical
Minimum Buffer Size
Rx
Impedance
Tx
Signal Characteristics
Clock / Data Relationship
Tx Clock Modes
Rx Clock Modes
Gap Clock (See Figure 13-4)
Tx / Rx Clock
Acquisition Range
Default
TA / CA
Selection:
Test
Operation
Signal Sense
Modules Per Modem
Cable Length to 52 Mbps
LED
Requirement
1 to 70 Mbps
Note: HSSI data rate limit of 70 Mbps may be reached before symbol rate limit is
reached.
One HSSI
ST, TT (or external) , SD, TA, CA, RT, RD, SG
DCE, 50-pin mini-D female per EIA-613 (HSSI)
Per EIA-612 (10KH ECL compatible).
Differential output voltage:
Differential Input voltage: 150 to 1000 mV pp with 110 load
5.0 mS smallest buffer setting, 0.1 mS step size, 32 mS maximum size
110 for TT, SD, TA
ST, CA, RT, RD will drive 110 and meet HSSI voltage levels
The A terminal is negative with respect to the B terminal for a binary 0 (Space or
OFF) state.
The A terminal is positive with respect to the B Terminal for a binary 1 (Mark or
ON) state.
The data transitions occur during the OFF to ON transition of the clock. Data is
stable during the ON to Off transition of the clock.
TT (Input clock) continuous.
ST (output clock) is continuous output, programmable in 1 bps steps or phase
locked to satellite clock
RT (output clock) is continuous from satellite, ST (internal clock), continuous
from TT
Not allowed – Send ST to external equipment so it will return a continuous clock
Asymmetrical clocking with Rx Doppler buffer disabled
Programmed Tx data rate ± 100 ppm
CA looped to TA
CA is asserted when there is no modem fault
I/O Loopback per the Appendix
Interface Loopback per the Appendix
Simplex (Tx only or Rx only) or full duplex
Programmable Normal or Inverted for TT and TD, RT and RD
The interface operates in Slot 1, Slot 2, or both slots.
2 m (6 ft) nominal, up to 15 m (49 ft) maximum – Note higher data rates usually
require shorter cable lengths.
Green LED indicates channel is enabled
Continuous Clock
Gap Clock
Figure 13-4. Continuous and Gap Clock at TT
> 590 mV pp into 110 load
13–4
Revision 1
MN-CDM710G
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