Comtech EF Data CDM-570/L Vipersat Parameter Editor - Manual (Page 67)

Chapter 2 - Using Parameter Editor 2-51
Vipersat
Maximum Power
Commissioning a terminal is following the calculated link budget before termi-
nal installation. Using these calculations, the maximum limit for modulator(s)
output power can be determined. This is the value entered in the Maximum
Power field shown in figure 2-33.
If more than one modulator is used at this location, that must also be taken into
consideration and applied to this value set point. The value set point assures that
the maximum power level is within the acceptable range for this modem and the
circuit.
The value entered sets the maximum power level allowed by all SCPC modula-
tors.
Target Eb/N0
Enter the desired operating receive level for closed loop servo control. This is
the value used by the receiving modem’s modulator to control its output power
level.
Speed Up Eb/N0
Normally, the DPC message is sent every 60 seconds from each terminal in the
network. If the target E
b
/N
0
value drops below the value set in the Speed Up
Eb/N0 box, the corresponding terminal increases its DPC message send rate to
every five seconds until the target value is greater than the Speed Up E
b
/N
o
value. This provides a loop speedup to rapidly regain link quality.
Target Range For No Power Adjust
The Target Range For No Power Adjust sets the differential between the
current E
b
/N
0
and the Target E
b
/N
0
value that, when reached, causes the modu-
lator to stop adjusting its power output. The default value for this parameter is
0.2 dB.
Target IP Address
In a VMS network, the VMS automatically assigns the Target IP Addresses.
The user will only need to fill in these addresses if the network configuration is
not a normal VMS configuration and requires a fixed IP address for DPC
communications.
Enter the IP address for the target transmitting site from which this unit will be
receiving. Up to four sites—such as for a CDD-564 quad demodulator—can be
entered.