Hardware reference guide

Modbus Plus NOM
35013379 02 October 2007 305
Self Healing Ring
Configuration
This configuration can be achieved by connecting the unused fiber optic ports of the
first and last NOM25200 directly or through the fiber optic repeater, if a mixed fiber
optic/twisted pairs network is used. This type of connection has all the advantages
of the previously described configurations, along with built-in redundancy. A broken
connection between any two Quantum modules in the ring will automatically
reconfigure the network to the Bus Configuration and continue the communication.
Node # 1
P/S CPU I/ONOM
I/O
211
Node # 2
P/S CPU I/O
NOM
I/O
211
490NRP254 Fiber Optic Repeater
Node # 3
P/S
CPU
I/O
NOM
I/O
252
Node # 4
P/S CPU I/O
NOM
I/O
252
Node # 5
P/S
CPU
I/O
NOM
I/O
252
MB+ Cable
Legend
Fiber Optic
Cable
MB+ Tap with
Terminator
MB+ Tap
Self-Healing Ring Configuration Example
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com