Introduction

There are three RJ45 Ethernet ports on the front of the CPU: one service port, and two device network ports. The ports share the characteristics described below.

Common Characteristics

All three ports have the same RJ45 connector and all use the same type of Ethernet cables.

NOTE: The three Ethernet ports are connected to chassis ground, and the system requires an equipotential ground.

Dust Cover

To keep dust from entering the unused Ethernet ports, cover the unused ports with the stopper:

Ethernet Ports

Each RJ45 connector has a pair of LED indicators:

The pin positions, pinouts, and cable connections are the same on all three RJ45 Ethernet ports:

Pin

Description

1

TD+

Pinout:

2

TD-

3

RD+

4

not connected

5

not connected

6

RD-

7

not connected

8

not connected

—

shell/chassis ground
NOTE: The TD pins (pins 1 and 2) and the RD pins (pins 3 and 6) can be reversed to allow the exclusive use of straight-through cables.

The ports have an auto MDIX capability that automatically detects the direction of the transmission.

It is required to use one of these Ethernet cables to connect to the Ethernet ports:

  • TCSECN3M3M••••: Cat 5E Ethernet straight-through shielded cable, rated for industrial use, CE- or UL-compliant

  • TCSECE3M3M••••: Cat 5E Ethernet straight-through shielded cable, rated for industrial use, CE-compliant

  • TCSECU3M3M••••: Cat 5E Ethernet straight-through shielded cable, rated for industrial use, UL-compliant

The maximum length for a copper cable is 100 m. For distances greater than 100 m, use fiber optic cable. The CPU does not have any fiber ports on it. You may use dual ring switches (DRSs) or BMX NRP •••• fiber converter modules to handle the copper-fiber conversion.

Ethernet Ports on Standalone CPUs

On standalone CPUs, the ACTIVE LED is green. The LNK LED is either green or yellow, depending on the status:

LED

LED Status

Description

ACTIVE

OFF

No activity is indicated on the Ethernet connection.

ON / blinking

Data is being transmitted and received on the Ethernet connection.

LNK

OFF

No link is established at this connection.

ON green

A 100 Mbps link* is established at this connection.

ON yellow

A 10 Mbps link* is established at this connection.

* The 10/100 Mbps links support both half-duplex and full-duplex data transfer and autonegotiation.

Service Port

The service port is the uppermost of the three Ethernet ports on the front panel of the CPU. This port can be used:

  • to provide an access point that other devices or systems can use to monitor or communicate with the M580 CPU

  • as a standalone DIO port that can support a star, daisy chain, or mesh topology of distributed equipment

  • to mirror the CPU ports for Ethernet diagnostics. The service tool that views activity on the mirrored port may be a PC or an HMI device.

NOTE: Do not used the service port to connect to the device network unless in some specific conditions described in Modicon M580, Open Ethernet Network, System Planning Guide.

The service port does not support the RSTP network protocol. Connecting the service port to the device network, either directly or through a switch/hub, can result in the creation of logical loops in the network, which can adversely affect network performance.

The service port does not support either VLANs or QoS tagging of Ethernet packets. The service port is inherently non-deterministic.

Device Network Dual Ports

When a CPU does not support RIO scanning, the two ports below the service port marked Device Network are DIO ports.

These CPUs do not support RIO scanning:

  • BMEP581020 and BMEP581020H

  • BMEP582020 and BMEP582020H

  • BMEP583020

  • BMEP584020

You may use a Device Network port to support a star, daisy chain, or mesh topology of distributed equipment. You may use both Device Network ports to support a ring topology.

When a CPU supports RIO scanning, the two ports below the service port marked Device Network are RIO ports. These CPUs support RIO scanning:

  • BMEP582040, BMEP582040H

  • BMEP583040

  • BMEP584040

  • BMEP585040, BMEP585040C

  • BMEP586040, BMEP586040C

  • BMEH582040, BMEH582040C

  • BMEH584040, BMEH584040C

  • BMEH586040, BMEH586040C

When used as RIO ports, both ports connect the CPU to the main ring in an Ethernet daisy-chain loop or ring.

For more information about RIO/DIO architectures, refer to the chapter Modicon M580 System.

Grounding Considerations

Follow all local and national safety codes and standards.