Cisco Systems UBR-3X10 manual Downstream Switch Module, as described in -3 on page

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