1-8
Cisco uBR-3x10 RF Switch Hardware Installation and Cabling Guide
OL-1984-06
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 I
2
C 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
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.
103287
Captive screw Captive screw
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
