Installation guide

Planning and Designing RIO Cable System

890 USE 101 00 October 2006

RIO System Design

Overview When designing an RIO cable system, consider:

z whether you will route one or two cables to the remote drops

z the node limitations—e.g., single-port or dual port, ASCII device support

z the expansion capabilities of the PLCs—i.e., the maximum number of drops

supported

z the number of nodes—head processors and drop adapters

z the locations and the environmental conditions in which these nodes must

operate

Key Elements in

a Cable System

Plan

The following are the key elements in a cable system plan:

z The cable system must be dedicated to RIO—no other signals or power can be

applied or transmitted on this network

z The attenuation between the head processor (or the last fiber optic repeater, if an

optical link is used) and any drop adapter must not exceed 35 dB at 1.544 MHz

(32 dB for the host-based 984 PLCs)

z minimum bend radiuses specified for the trunk and drop cables must not be

exceeded

z expansion and contraction loops should be put into the cable system to allow for

temperature changes

z band marked trunk cable is useful for determining tap placement

z the cable system should be single-point grounded within 20 ft. of the RIO

processor—the central ground point may be a tap, a splitter, or a ground block

z the physical cable installation must be well supported, and cable pull strength

must be considered; some manufacturers suggest that RG-6 and RG-11 cable be

supported at least every 50 ft; contact the manufacturer to ensure that you do not

exceed the strain limit of the cable.

z where rodents may be a problem, protect the cable installation by using conduit

or a similar material

z precautions should be taken when the media components are installed in hostile

environments where high temperatures or corrosives exist—consult cable

manufacturers and/or CATV suppliers for other special products for harsh

environments

Note: Document your decisions for the installer and for future reference by

maintenance personnel. Use the forms provided in Planning RIO Drops, p. 61 to

document the system.

This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com