Rf Control Modes; Figure 5-2. Example: Accessing Chpa Features - CPI Satcom Division VZU-6997 Series Installation, Operation And Maintenance Manual

5.12 RF Control Modes

The CHPA features two RF Control modes:
•
ALC (Automatic Level Control) mode (ALC is displayed on Line 1)
•
Open Loop mode (nothing special is displayed)
Either mode may be selected under the RF Control category. Press the MENU button until Line
3 displays RF CONTROL; press the FUNCTION button until Line 3 displays RF MODE (see the
next subsection, "Special CHPA Functions," for access to menu categories and Appendix B for a
detailed listing of all menu categories).
In ALC mode, the microprocessor controller adjusts the attenuator to maintain the RF output
power meter reading within ±0.1 dB of the RF output power setting (within the adjustment
limits of the attenuator and RF output limits of the CHPA). During Standby, the CHPA remains
in ALC mode, but the Attenuator Setting is frozen. If ALC is chosen while the unit is in
Standby, the attenuator will be set to maximum attenuation.
While in ALC mode, if the RF Output Power drops below 10 watts (W), the Attenuator Setting
is frozen until the RF Output Power exceeds 10 watts, or a new RF output power request is
made by the user. The CHPA will remain in ALC mode. This feature prevents the attenuator
from being adjusted to 0 dB if RF is removed from the unit.
If the user directly sets the attenuator during ALC mode, the CHPA will revert to Open Loop
RF Control mode.
In Open Loop mode, the microprocessor controller adjusts the attenuator to meet a requested
RF output power setting. Once that setting is attained (±0.1 dB), the Attenuator Setting is fixed
until the next Attenuator Setting or RF output power request is made by the user.
Catagory Title
Press the MENU button
to toggle through available
catagories.
D .01023245 R .L
OC EV
L O CAL
S T A N D B Y
C I F C O N F I G U R A T
B A U D R A T E :
Function Title

Figure 5-2. Example: Accessing CHPA Features

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REPRODUCTION OR RELEASE WITHOUT EXPRESS PERMISSION IS STRICTLY PROHIBITED
1 1 : 0 0 P
I O N
9 6 0 0
Entry
When these arrows are displayed,
use the arrow keys to toggle through
the available entries.
CHPA SERIES
When this triangular
symbol appears, press
the FUNCTION button
to scroll through the
available Functions.
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