Rockwell Automation 57C329 Remote I/O Communications, AutoMax - Manual (Page 119)

KĆ1
K1.0 INTRODUCTION
This appendix provides an overview offiberĆoptic networks, a
description ofthe hardware components that comprise the AutoMax
fiberĆoptic Remote I/O network, and guidelines for installing the
components and fiberĆoptic cable. Refer to sections 3.5 and 3.6 in
this manual for module installation and replacement procedures.
K1.1 FiberĆOptic Remote I/O Network Overview
An AutoMax Remote I/O network can be built using coaxial cable or
fiberĆoptic cable. FiberĆoptic cable is recommended when the
following factors are required by the application:
D High noise immunity Ć FiberĆoptic cable is not affected by
electromagnetic interference and can be installed with other
signal or power wiring.
D Isolation Ć Ground loops and spurious signals are prevented
since there is no electrical connection between the two ends of
the fiberĆoptic transmission system.
D Safety Ć FiberĆoptic cable can be used in chemical plants, as well
as in oil and gas refineries, since glass is unaffected by most
chemicals or solvents. Breaking a fiber will not create a spark
leading to a potential explosion. In addition, since there is no
electrical current flowing, exposure to water will not cause a short
circuit in the fiberĆoptic cable.
D Distance Ć Fiber normally has much lower attenuation that
copper. Therefore, longer links can be constructed with
fiberĆoptic cable than with copper (coaxial) cable.
Unlike the coaxial cable network, which allows multiple drops to be
connected to a main trunkline, a fiberĆoptic link provides
pointĆtoĆpoint communication only. Therefore, a different network
configuration and different hardware components are required to
enable communication between drops. A star topology" network
configuration is used for the fiberĆoptic Remote I/O network, as
shown in figure K1.1.
The type of cable or the network configuration used has no effect on
the operation ofthe Remote I/O network protocols, application
software, or the operation of the Remote I/O module, the Shark
Interface module, the Remote I/O Head, or the Remote Drive
Interface Head.