Comtech EF Data CDM-425, Installation And Operation Manual

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CDM-425 Advanced Satellite Modem
Revision 0
Appendix C C–2 MN-CDM-425
C.2 Setting AUPC Parameters
The important consideration is that EDMAC framing should be enabled .
1. Use the SELECT: Configuration

Mode menu to first select EDMAC framing. You
may select EDMAC as IDLE , or define the unit as an EDMAC Master or Slave .
2. Verify that the remote modem also has EDMAC framing enabled.
3. Set the nominal output power of the modem: Use the SELECT: Configuration

Tx

POWER menu to select MANUAL mode, and then edit the displayed Tx output power
level.
4. Select AUPC as the operating mode. At this point, you are prompted to define four key
parameters: Target Eb/No , Max Range , Alarm , and Demod Unlock .
C.2.1 Target Eb/No
This is value of Eb/No that you need to keep constant at the remote modem:
•
The minimum value to enter is 0.0 dB. If the Eb/No falls below this value, the AUPC
control will increase the Tx output power, but will never exceed the value determined by
the parameter
MAX RANGE .
•
The maximum value to enter is 14.9 dB. If the Eb/No exceeds this value, the AUPC
control will reduce the Tx output power, but will never drop below the nominal value set.
•
The default value is 3.0 dB
•
The resolution is 0.1 dB
If IP-ACM mode is selected, then the larger Eb/No value does not need to be
specified. The combined AUPC/ACM algorithm does not require this parameter.
C.2.2 Max Range
This defines how much the modem is permitted to increase the output level, under AUPC control:
•
The minimum value to enter is 0 dB.
•
The maximum value to enter is 9 dB.
•
The default value is 1 dB.
•
The resolution is 1 dB.
C.2.3 Alarm
This defines modem behavior if the maximum power limit is reached while under AUPC control.
The two choices are:
•
NONE (no action) – default setting
•
Tx ALARM (generate a Tx alarm)