Omron NE1A-SCPU01 - 07-2009 Operation Manual page 93

Wiring
Switching Hub Installation
Environment Precautions
Switching Hub
Connection Methods
Hub
Connector Connector Connector
GR GR
STP
(Shield)
• Press the cable connector in firmly until it locks into place at both the
switching hub and the NE1A-series Controller.
• Do not lay the twisted-pair cable together with high-voltage lines.
• 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.
• Do not ground the switching hub in the same location as a drive-system
component such as an inverter.
• Always use a dedicated power supply for the switching hub's power sup-
ply. Do not use the same power supply used for other equipment, such as
an I/O power supply, motor power supply, or control power supply.
• Before installation, check the switching hub's environment-resistance
specifications, and use a switching hub appropriate for the ambient condi-
tions. Contact the switching hub manufacturer for details on switching
hub's environment-resistance specifications.
• 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
appearance. Incorrect cables will cause communications to fail. We
recommend using cascade connections with straight cables when-
ever possible.
MDI ports
MDI-X port
(cross)
Switching
Hub
• Some switching hubs can automatically distinguish between MDI and
MDI-X. When this kind of switching hub is being used, straight cable can
be used between switching hubs.
Hub
Connect shield.
Connector Connector
Do not connect shield.
Connector
STP
(Shield)
STP
(Shield)
Switching
Hub
Switching
Hub
Section 3-2
ED Router
FG
terminal
ED Router
Connector
FG
terminal
: Straight cable
: Cross cable
Switching
Hub
59