High Density Transmitter Operation; High Density Transmitter Optical Output; Laser Warning - Cisco Prisma II 1550 nm Installation And Operation Manual

Chapter 1 Module Introduction

High Density Transmitter Operation

The Prisma II High Density Transmitter receives an RF signal through a connector
on the back of the module. The RF input signal is amplified before being converted
to an optical signal using a high-performance, isolated distributed feedback (DFB)
laser.
The incoming RF signal is also routed through a coupler to an RF detector circuit.
The RF detector produces a DC voltage proportional to incident RF power that is
used to monitor the input power level. The transmitter generates an alarm condition
if input power rises above or falls below a specified level.
Transmitter gain is controlled through the selection of Manual or Automatic Gain
Control (AGC) mode operation.
In Manual mode, an attenuator can be used to reduce RF power in an overdrive

condition or to compensate for variations in transmitter gain. Any manual
attenuator adjustments are reflected in the indicated RF drive level. It may be
desirable to make such adjustments to compensate for power differences if the
channel load differs from the specified value.
In AGC mode, the microprocessor monitors the actual input composite power

and adjusts the attenuator to maintain constant RF drive level into the laser
diode.
After the RF amplification and control stage, the signal is equalized and impedance-
matched, and then is sent to the laser. The optical output connector is located on the
front panel of the module.
The user can turn the laser on or off, adjust the drive level to the laser, and set alarm
levels. The module can be controlled either locally using an ICIM front-panel
interface, or remotely using LCI or TNCS software, CLI commands, or the ICIM Web
Interface.

High Density Transmitter Optical Output

Depending on how you ordered your system, the optical output connectors may be
either SC/APC, SC/UPC, or E2000/APC.

Laser Warning

WARNING:
Avoid damage to your eyes! Do not look into any optical connector while the
system is active. Even if the unit is off, there may still be hazardous optical
levels present.
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