Comtech EF Data CDM-570 - Manual (Page 188)

CDM-570/570L Satellite Modem with Optional IP Module Revision 12
Automatic Uplink Power Control MN/CDM570L.IOM
9–2
9.2 Setting AUPC Parameters
Step Task
1
Under the menu (CONFIG ÆFrame), first ensure that Framing is selected. EDMAC or
EDMAC-2 may be selected, then the Framing mix – either AUPC-Only or AUPC
+EDMAC. The important consideration is that EDMAC framing should be enabled.
2 Verify that the remote modem also has EDMAC framing enabled.
3
Under the menu (CONFIG ÆTxÆPower), set the nominal output power of the modem
by selecting the Manual mode, then editing the Tx output power level displayed.
4 Select AUPC as the operating mode.
At this point, the system prompts definition of four key parameters: Target E
b
/N
0
, Max Range,
Alarm, and Demod Unlock.
9.2.1 Target E
b
/N
0
Target E
b
/N
0
is value of E
b
/N
0
that is desired to keep constant at the remote modem.
If the E
b
/N
0
exceeds this value, the AUPC control reduces the Tx output power, but never drops
below the nominal value set.
If the E
b
/N
0
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 minimum value to enter is 0.0 dB
• The maximum value to enter is 14.9 dB
• The default value is 3.0 dB
• The resolution is 0.1 dB
9.2.2 Max Range
Max-Range defines how much the modem is permitted to increase the output level while 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
9.2.3 Alarm
The Alarm parameter defines how the modem acts if the maximum power limit is reached while
under AUPC control. The two choices are:
• None (no action)
• Tx-Alarm (generate a TX alarm)
The default setting is None.