Motorola SG4-DRT-2X Instruções de Operação descarregar pdf (Página 89)

Modules 4-17

SG4000 Installation and Operation Manual

Ingress Control

The SG4000 platform incorporates electronic ingress control switching, enabling you to choose

one of three options for troubleshooting noise sources. A maximum of four switches (one ingress

switch per RF module) can populate the SG4000. Figure 4-7 illustrates the ICS location on the

RF module.

Ingress switches are controlled in one of two ways: (1) remotely, through the optional on-board

LL-SG4 transponder in communication with the status monitoring system; or (2) locally, using

the embedded plug-in module (EPIM).

The three states of the switch and their functions include:

State Description

–40 dB

Effectively isolates the contaminated leg by adding a minimum of 40 dB attenuation.

–6 dB

Typically initiated at the headend, it provides –6 dB additional attenuation to the return signal. This

is useful in diagnosing noise presence without interfering with normal service.

Completes the return path without alteration to the return signal.

To activate the Ingress Control Switch locally using the EPIM:

1 Confirm that an ICS switch is installed in each of the RF modules. You must remove the

SG4-RF chassis cover to access the ICS location.

2 Using the 8-position DIP switch S2 on the EPIM, locate the housing port number of the RF

module you wish to activate. See Figure 3-1.

3 Place the switch in the middle position to add −6 dB of attenuation or in the −40 dB position

(Figure 4-7) to completely attenuate that particular RF return path. LED D5 on the EPIM

should illuminate, indicating that the switch is activated.

4 Verify the drop in noise/signal level by measuring the RF –20 dB return test point on the

respective transmitter that the RF module is connected to.

Status Monitoring

Table 4-10 identifies the status monitor reporting and control provisions built into the SG4000

platform. Refer to the transponder installation manual for operation.

Table 4-10

SG4000 reporting and control provisions

Parameter

Receiver Control

Redundant Receiver Switching

Receiver Telemetry

Optical Input Power

Receiver DC current draw

Receiver Identification

Receiver enable or disable

1 2 ... 84 85 86 87 88 89 90 91 92 93 94 ... 107 108

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Motorola SG4-DRT-2X Instruções de Operação Página 89