Cisco Prisma II Installation And Operation Manual page 13

Reverse video receiver and reverse data receiver

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Prisma II Reverse Receiver Operation

The two reverse receivers are used in conjunction with a reverse transmitter to

receive reverse path signals to the hub or headend.

The two reverse receivers each contain two separate optoelectronic receivers. Optical

input is through two optical connectors mounted on the front of the module. The RF

output is through two connectors on the rear of the module.

In the reverse receiver, the optical signal is detected by a photodiode and is

converted to an electrical signal. The electrical signal is then sent to an RF amplifier

with approximately 24 dB of gain for the video/data module, and approximately 30

dB of gain for the data only module. The RF signal goes to its respective output

connector on the rear of the module.

Using the ICIM, LCI, or TNCS, each RF output may be attenuated as much as 20 dB

relative to no attenuation, in 0.5 dB increments. The actual RF output levels of the

dual reverse receiver (minus 20 dB) can be monitored at the two -20 dB test points on

the front panel.

The reverse receiver can be controlled by an ICIM, the LCI software, or the TNCS

software.

Optical Input

Depending on how you ordered your system, the optical input connectors may

either be an SC/APC, SC/UPC, FC/UPC, or E2000/APC.

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.

78-713378-01 Rev C

Introduction

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