Comtech EF Data CDM-625 User Manual
Page 355
CDM-625 Advanced Satellite Modem
Revision 15
DoubleTalk
Carrier-in-Carrier Option
MN-CDM625
10–25
connection is available to the distant end that does not depend on the satellite link for
primary connectivity, the setup can be performed remotely.
Once the link is established, a further rebalance, activation or suspension does not require
another person to be present, or independent remote IP access.
2.
Once the ‘normal’ CnC link has been established, determine that the link is stable and that it
has an acceptable link margin at both ends.
3.
Decide, arbitrarily, which is Side A, and which is Side B.
4.
From the CDM-625 front panel, select the CONFIG CnC Mode menu:
CnC Mode: APC,Side A,C-Band (Off, On, APC)
Activate? N (Y,N) APC is not active ()
On the top line, use the
▲▼
arrow keys to select the appropriate CnC operating mode.
Available selections are:
•
Off
•
On (normal)
•
APC,Side A,C-Band
•
APC,Side A,X-Band
•
APC,Side A,Ku-Band • APC,Side A,Ka-Band
•
APC,Side B,C-Band
•
APC,Side B,X-Band
•
APC,Side B,Ku-Band
•
APC,Side B,Ka-Band
If it is not known which satellite band is being used, no attempt should be
made to engage CnC-APC.
Once the mode has been selected, press ENTER – do not select Activate (on the bottom
line) yet. Note the following:
• If Side A is selected at both sides, or Side B is selected at both sides, both modems
will display a Frame Sync fault (under Rx faults). No further action is possible until
this error has been corrected.
• If different satellite bands are selected on each side (for instance, Side A is Ku-Band,
while side B is C-Band) the modem will display an APC Band Mismatch fault (under
Rx faults). No further action is possible until this error has been corrected.
5.
Based on the known RF terminal equipment in use, determine a value for the maximum
allowed power increase (TPLI
max
) and then set this value. From the CDM-625 front panel,
select the CONFIG Tx Power menu:
Output Power Mode = CnC-Auto-Power-Control
Level = -25.0dBm MaxPwrIncrease=2.5dB ()