Rockwell Automation 1761-NET-ENIW MicroLogix Ethernet Interface (ENI) User Manual - Manual (Page 28)

Publication 1761-UM006E-EN-P - August 2005
2-6 Installation and Wiring
When to use straight-through and cross-over cables:
• ENI/ENIW Ethernet port to 10/100-Base-T Ethernet switch cables
utilize a straight-through pin-out (1-1, 2-2, 3-3, 6-6).
• Direct point-to-point 10/100-Base-T cables connecting the
ENI/ENIW Ethernet port directly to another ENI/ENIW Ethernet
port (or a computer 10/100-Base-T port) require a cross-over
pin-out (1-3, 2-6, 3-1, 6-2).
Ethernet Cables
Shielded and non-shielded twisted-pair 10/100-Base-T cables with
RJ45 connectors are supported. The maximum cable length between
an ENI/ENIW Ethernet port and a 10/100-Base-T port on an Ethernet
switch (without repeaters or fiber) is 100 meters (323 feet). However,
in an industrial application, the cable length should be kept to a
minimum.
With media converters or Ethernet switches, you can also connect to
the following media:
• fiber optic
• broadband
• thick-wire coaxial cable (10-Base-5)
• thin-wire coaxial cable (10-Base-2)
Maintain ENI and ENIW Cable Connections
The unshielded twisted pair (UTP) patch cable on a switch should be
labeled and treated as dedicated. Be careful when moving any cables,
as port identity may be effected. If you are using a switch and must
move the ENI/ENIW to a new port for any reason, power-cycle the
interface. The power cycle forces a new Address Resolution Protocol
(ARP) sequence which should immediately associate the ENI/ENIW’s
IP address with the port it is connected to.
To help prevent problems with network communications affected by
moving cables, discourage any field personnel from treating the ports
of a switch as “all the same”.