CDM-625 Advanced Satellite Modem
Revision 1
Introduction
MN-0000036 (Ref MN/CDM625.IOM)
the Modem. The EDMAC channel may also be used to convey M&C data to a Transceiver at the
distant end of a satellite link, if it is connected to a CDM-625.
Additionally, the CDM-625 incorporates an FSK serial link that can be activated on the Tx-IF
port for the purpose of communicating with an FSK capable ‘smart’ BUC. This link is designed
to be compatible with the Global VSAT Forum/ND-Satcom specification. In this manner, a user
may monitor, configure, and control the BUC using the front panel display and keypad of the
modem or the modem’s remote control interface. The EDMAC channel can be used to convey
M&C interface to a BUC at the distant end of a satellite link if it is connected to a CDM-625.
1.5
Compatibility
The CDM-625 is fully backwards-compatible with the Comtech EF Data CDM-500, CDM-550,
and CDM-550T modems (not including sequential FEC). Being an Open Network Modem, the
CDM-625 is fully compatible with modems from other manufacturers that are compliant with the
IESS-308/309/310/314 specifications. Note, however, that IESS-315 (VSAT Turbo) defines
closed network operation, and this therefore requires modems from the
same manufacturer
at
both ends of the link.
It is also fully backwards compatible with the CDM-600 and CDM-600L modems (with the
exception of sequential FEC, and a lower data rate range of 18 kbps). The CDM-625 includes
software emulation of CDM-600 and CDM-600L.
1.6
New in this Release
Version 1.1.5 firmware adds the following new features:
•
G.703 Clock Extension Mode
is added
. See
Chapter 9. CLOCK MODES AND DROP
AND INSERT (D&I)
for details.
•
A new Tx timing mode is added. External TT
is used for transmit timing with ST derived
from Rx Satellite timing. This is referred to in this manual as
Ext-TT (ST = RxSat)
.
•
A new alarm mask is added.
Now, users can selectively mask loss of external lock signal
on all serial synchronous interfaces, including G.703.
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