Installation guide

Planning and Designing RIO Cable System
48
890 USE 101 00 October 2006
Tap Connections and Locations
Overview Each tap has three ports—a trunk-in port, a drop cable port, and a trunk-out port; the
RIO cables connect to the tap ports via F connectors. The taps come mounted to a
plastic block that is used to isolate them from ground. They must be surface
mounted to a wall or an enclosure. Make sure that no tap in the RIO system is
grounded or touched by a grounded metallic surface unless it is being used
intentionally as the single grounding point for the entire system.
Using Band
Marked Trunk
Cable
Improper placement of taps can cause signal reflections and distortion of the signal
waveform. Proper placement will keep these reflections to a minimum and avoid
problems with waveform distortion. The preferred method of tap placement is on
cable band markers.
Trunk cable with band markers applied at regular intervals should be purchased
from the manufacturer. Intervals will vary based on the propagation of the cable.
Modicon RG-11 trunk cable is band marked at 8.86 ft (2.7 m) intervals; RG-6 cable
is not band marked. If you are not using Modicon RG-11 for trunk cable, you can
instruct your cable manufacturer to apply marker at the required intervals. The cost
to perform band marking is very small.
Tap Port
Connections
An RG-11 cable can connect directly to a tap port F connector via a Modicon
490RIO00211 F Connector installed on the end of the cable (see F Connectors for
Coaxial Cables, p. 78).
Quad shield RG-6 cable can be connected to a tap port F connector via a Modicon
MA-0329-001 F Connector (see F Connectors for Coaxial Cables, p. 78).
Semirigid cable is more difficult to connect to the two (trunk-in and trunk-out) F
connector ports on the tap. Because there is only a 1 in. space between the two
ports, you may not be able to fit semirigid connectors directly on both ports. To avoid
this problem, we recommend that you use high quality 90° right angle F adapters
such as the Modicon 52-0480-000 Right Angle F Adapter (see F Adapters for
Semirigid Cable, p. 80).
Note: If taps are placed too close to each other (or too close to a splitter in a Hot
Standby system), a cumulative reflection will result. To avoid this problem, install
taps at least 8 ft 2 in. (2.5 m) away from one another.
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com