Chapter 1 Cisco uBR-3x10 RF Switch Overview

Hardware Component Descriptions

Downstream Switch Module

Cisco part number 74-2623-01 (See Figure 1-6 on page 1-8)

Three downstream (high-frequency) switch modules are used in the Cisco uBR 3x10 RF Switch. The module operates from 54 to 860 MHz. Each downstream switch module has ten 75-ohm inputs accessed through the CABLE PLANT MCX connectors on the backpanel of the RF switch. During normal system operation, the downstream switch module switches all direct traffic to their respective default termination interfaces.

Note See Chapter 4, “Cabling the RF Switch With the Cisco uBR10012 CMTS Cable Interface Line Cards,” for more cabling information.

The downstream switch module accepts signal inputs (eight) from the power combiner and combines one of the eight to a protect output. Alternately, the switch splits the inputs into two groups of four and then selects one input (in the group of four) to combine with the protect input. The relays are electromechanical, latching relays that are controlled through an I2C interface. The switch card provides a minimum of 60 dB of isolation from connector port to connector port.

Figure 1-6 Downstream Switch PCB Assembly

103287

 

 

 

 

 

Captive screw

Captive screw

 

 

 

 

Each downstream switch board contains a set of four LEDs that indicates the working status of the port

 

 

 

 

as described in Table 1-3 on page 1-8.

 

 

 

 

 

 

Table 1-3

 

Downstream Switch Board LED Descriptions

 

 

 

 

 

 

 

 

 

 

 

 

LED Name

 

Color

Description

 

 

 

 

 

 

 

 

 

 

 

 

Protect 1

 

Green/Yellow

Indicates CMTS/PROTECT 1

 

 

 

 

 

 

 

 

 

 

 

 

Protect 2

 

Green/ Yellow

Indicates CABLE PLANT/PROTECT 2

 

 

 

 

 

 

 

 

 

 

 

 

Error 1

 

Off/Yellow

Indicates a channel problem 1

 

 

 

 

 

 

 

 

 

 

 

 

Error 2

 

Off/Yellow

Indicates a channel problem 2

 

 

 

 

 

 

 

 

 

 

Cisco uBR-3x10 RF Switch Hardware Installation and Cabling Guide

 

 

 

 

 

 

 

 

 

 

 

 

 

1-8

 

 

 

 

 

OL-1984-06

 

 

 

 

 

 

 

 

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Cisco Systems UBR-3X10 manual Downstream Switch Module, Color Description