Precautions When Installing And Connecting Ethernet Switches - Omron sysmac NX102-9 Series Owner's Manual

2 Installing Ethernet Networks
2-2-4

Precautions When Installing and Connecting Ethernet Switches

Precautions When Installing Ethernet Switches
• Do not ground the Ethernet switch in the same location as a drive-system component, such as an
inverter.
• Always use a dedicated power supply for the Ethernet switch's power supply. Do not use the same
power supply for other equipment, such as an I/O power supply, motor power supply, or control
power supply.
• Before installation, check the Ethernet switch's environmental resistance specifications, and use an
Ethernet switch that is appropriate for the ambient conditions. Contact the Ethernet switch manufac-
turer for details on Ethernet switch's environmental resistance specifications.
Ethernet Switch Connection Methods
• To connect Ethernet switches with twisted-pair cables, observe the followings:
Connect an MDI port to an MDI-X port with a straight cable.
Connect two MDI ports or 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 cascade connections with straight cables whenever possible.
MDI-X port (cross)
• Some Ethernet switches can automatically distinguish between MDI and MDI-X. When this kind of
Ethernet switch is used, straight cable can be used between Ethernet switches.
Precautions for Correct Use Precautions for Correct Use
Adjust the built-in EtherNet/IP port's link settings to match the communications settings of the
connected Ethernet switch. If the settings do not match, the link will be unstable and prevent nor-
mal communications. The following table shows the allowed settings for each Ethernet switch
communications mode. (Auto-Nego: Auto negotiation, Full: Full duplex, Half: Half duplex)
Ethernet switch
Auto-Nego
10 Mbps (fixed)
100 Mbps (fixed)
1,000 Mbps (fixed) Full
Best = Recommended; OK = Allowed; --- = Not allowed.
2-10
MDI port
Ethernet switch
Ethernet
Ethernet
switch
switch
Auto-
Nego
Best
Full ---
Half OK
Full ---
Half OK
---
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User's Manual (W506)
Straight cable
Cross cable
Ethernet
switch
Built-in EtherNet/IP port
10 Mbps (fixed) 100 Mbps (fixed)
Full Half Full
--- OK ---
OK --- ---
--- OK ---
--- --- OK
--- --- ---
--- --- ---
1,000
Mbps
(fixed)
Half Full
OK ---
--- ---
--- ---
--- ---
OK ---
--- Best