Ethernet Port Uses

The Ethernet port supports the following types of communication:

  • peer communications with other Momentum PLCs

  • communication with a higher-level PLC: The Ethernet port can be polled by–or push data to–a higher-level PLC.

  • SCADA/HMI communication: The Ethernet port can be polled by a SCADA or HMI for monitoring, and can push data to a SCADA via an unsolicited write transaction.

  • communication with devices and systems on other networks: for example via a gateway

  • I/O scanning, programming, monitoring, and maintenance over the plant network

  • Global Data service for the 171 CBU 98091 processor

Ethernet Port Features

The features of the Ethernet port include:

Feature

Description

Addressing

  • Unique IEEE global (MAC) address

  • User assigned IP address

Application protocols supported

  • DHCP/BootP

  • Global Data (on the 171 CBU 98091 processor)

  • HTTP (web server)

  • I/O scanner

  • Modbus protocol messaging

  • SNMP

Auto MDI/MDI-X

Supported

Auto negotiation

Supported

Connector type

Shielded RJ45 female

Max connections: Modbus TCP (port 502)

  • 16 connections over the Ethernet port

  • 4 connections over the USB port

Max connections: web (HTTP)

2

Max client requests per cycle

4

Max server requests per cycle

4

Max message length

  • 1026 bytes (on Ethernet or USB) including network headers

  • 253 for Modbus requests

  • 1019 for UMAS protocol requests

Max message throughput for Modbus TCP

The Ethernet Environment (or CPU load) identified in the Bandwidth window:

  • Isolated

  • Mastered

  • Open

Ethernet Services

The Ethernet port supports the following Ethernet services: