Autosetup, Automatic Gain Control, And Manual Gain Control; Autosetup - Harmonic PWRLink II 4100S Series Product Manual

Transmitter Setup
4.3 Autosetup, Automatic Gain Control, and Manual
Gain Control
The Autosetup feature enables you to quickly set the internal drive level to the
laser as close as possible to the optimal value determined at the Harmonic
factory. The transmitter operates in either the Automatic Gain Control (AGC)
mode or the Manual Gain Control (MGC) mode.
4.3.1

Autosetup

What does Autosetup achieve?
The Autosetup feature calibrates and automatically adjusts the internal
RF pad for very close-to-optimum modulation performance.
How does Autosetup operate?
The Autosetup procedure works in three steps:
1. When you enter the Autosetup command via the HLP 4200WD front
panel, the transmitter's internal microprocessor measures the input drive
level to the transmitter. Then, it sets the attenuator pad so that the average
RF drive level to the laser is at the same optimal value determined at the
Harmonic factory using CW carriers.
2. Once this is done, the menu asks you to choose between CW Mode and
Video Mode.
- By entering CW Mode, you leave the current internal RF pad value as it
stands.
- By entering Video Mode, you add 3 dB to the current internal RF pad
value.
3. Finally, you need to select AGC or MGC mode of operation. See Section
4.3.2 Automatic Gain Control and Manual Gain Control.
4–4
Figure 4-1. Autosetup via the HLP 4200 front panel
Copyright © 2006 Harmonic Inc.