Installation guide
Network Infrastructure for EtherNet/IP™
Planning the Infrastructure
3-19
Recommended Cable Practice
Different cable types can be distinguished through the use of different colored outer cable jackets.
Most infrastructure components automatically compensate for the type of device connected. This is
known as auto-crossover or auto MDI/X capability.
There are two classes of Ethernet devices: Data Communications Equipment (DCE) refers to
infrastructure components, and Data Terminal Equipment (DTE) refers to control devices. The following
connection schemes normally apply:
• DCE to DCE (infrastructure components connected to infrastructure components):
crossover cable
• DTE to DTE (control devices connected to control devices): crossover cable
• DTE to DCE (control devices connected to infrastructure devices): 1:1 straight-through
cable
3.3.3.5 Other Options
Like device-level networks, a variety of cable options are available for easier wiring in specific
application situations (e.g., in cabinets versus outside of cabinets). See 4.4 Layout and Wiring
Considerations for more details.
3.3.3.6 Future Options
The IEEE Std 802.3af task group is working on DTE powering, which will enable switches and other
DCE equipment with integrated power supplies to provide dc power for unpowered DTE equipment.
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Power will be carried either by signal pairs 1 & 2 and 3 & 6, or by unused pairs 4 & 5 and 7 & 8. This
capability can provide power to sensors and video equipment as well as security devices and wireless
access points, extending the flexibility of subnetworks.
3.3.4 Applicable IEEE Standards for Fiber-Optic Ethernet
Fiber-optic cable mediums provide longer distance runs than wire as well as immunity from electrical and
radio frequency (RF) noise. The major IEEE standards that apply to industrial fiber-optic Ethernet
installations are 10 Base-FL for 10 Mbps connections and 100 Base-FX for 100-Mbps (fast Ethernet)
operation; 1000 Base-SX refers to IEEE Std 802.3z for 1-Gbps (or Gigabit Ethernet).
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3.3.4.1 Glass Fiber Cable
The fiber-optic cable typically used in both 10-Mbps and 100-Mbps industrial Ethernet applications is
based on 62.5-micron duplex multimode glass cable. Also available are 50- and 100-micron fibers.
Maximum cable lengths are based on the type of cables used and whether full-duplex or half-duplex
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IEEE 802.3, http://standards.ieee.org/getieee802/portfolio.html
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IEEE 802.3, http://standards.ieee.org/getieee802/portfolio.html