Ethernet Port

Overview

The M251 Logic Controller is equipped with Ethernet communications ports:

Reference

Number of Ports

Port Name

TM251MESC

2 (one dual Ethernet port switch)

Ethernet 1

TM251MESE

2 (one dual Ethernet port switch)

Ethernet 1

1

Ethernet 2

Characteristics

This table describes the different Ethernet characteristics:

Characteristic

Description

Function

Modbus TCP/IP, Machine Expert protocol, EtherNet I/P

Connector type

RJ45

Auto negotiation

From 10 Mbps half duplex to 100 Mbps full duplex

Cable type

Shielded

Automatic cross-over detection

Yes

Pin Assignment

This figure shows the RJ45 Ethernet connector pin assignment:

This table describes the RJ45 Ethernet connector pins:

Pin N°

Signal

1

TD+

2

TD-

3

RD+

4

-

5

-

6

RD-

7

-

8

-

NOTE: The controller supports the MDI/MDIX auto-crossover cable function. It is not necessary to use special Ethernet crossover cables to connect devices directly to this port (connections without an Ethernet hub or switch).
NOTE: Ethernet cable disconnection is detected every second. In case of disconnection of a short duration (< 1 second), the network status may not indicate the disconnection.

Status LEDs

These figures show the RJ45 connectors status LEDs:

Ethernet 1

Ethernet 2

This table describes the Ethernet status LEDs:

Label

Description

LED

Color

Status

Description

1

Ethernet link/speed

Green/Yellow

Off

No link

Solid yellow

Link at 10 Mbps

Solid green

Link at 100 Mbps

2

Ethernet activity

Green

Off

No activity and no link

On

The link is detected, but there is no activity

Flashing

Transmitting or receiving data