Omron CS1W-ETN21 User Manual

Page 61

Network Installation

Section 2-4

• Do not lay the twisted-pair cable near devices that generate noise.

• Do not lay the twisted-pair cable in locations subject to high temperatures

or high humidity.

• Do not lay the twisted-pair cable in locations subject to excessive dirt and

dust or to oil mist or other contaminants.

Hub Installation
Environment Precautions

• Do not install the hub near devices that generate noise.

• Do not install the hub in locations subject to high temperatures or high

humidity.

• Do not install the hub in locations subject to excessive dirt and dust or to

oil mist or other contaminants.

Hub Connection Methods

If more hub ports are required, they can be added by connecting more than
one hub. There are two possible connection methods for hubs: Cascade and
stacked.

Cascade Connections

• Connect two hubs to each other as follows: Connect an MDI port to an

MDI-X port with a straight cable; connect two MDI ports with a cross
cable; and connect two MDI-X ports with a cross cable.

Note

It is very difficult to distinguish cross cables and straight cables by appear-
ance. Incorrect cables will cause communications to fail. We recommend
using cascade connections with straight cables whenever possible.

• With cascade connections, up to 5 segments can be connected using up

to 4 repeaters (i.e., 4 hubs).

Stack Connections

• Connect the hubs using special cables or special racks.

• Normally there is no limit to the number of hubs in a stack, and each stack

is treated as one hub. Some hubs, however, are limited in the number of
hubs per stack.

MDI-X port
(cross)

Hub

Straight cable
Cross cable

Hub

MDI ports

Hub

Four stackable hubs

Stack cable

Two stackable hubs

Stack cable