Chapter 3

Operation Overview

Allocation of Ethernet Connections

Operation

This chapter describes ENI operation. The following information is included:

•Operation Overview

•Allocation of Ethernet Connections

•ENI Functional Overview

•Program Upload/Download and On-Line Sessions

Ethernet is the protocol used to transport TCP/IP messages. On top of TCP, Ethernet/IP is the open protocol used by the ENI. Ethernet/IP allows devices to exchange information (data); or to upload, download, and edit logic programs over Ethernet.

To communicate between devices, Ethernet/IP uses a “connection” model. Connections are dedicated paths across Ethernet between devices.

The ENI supports a maximum of 6 connections, allowing simultaneous communication with up to 6 other devices or applications. The connections are dedicated as follows:

Number of Connections

Dedicated to:

 

 

2

outgoing messages

 

 

2

incoming messages

 

 

2

either incoming or outgoing messages

 

 

 

TIP

For peer connections, no more than one connection

 

per destination node is established. If multiple MSG

 

 

 

 

 

 

instructions use the same destination node, they use

 

 

 

 

the same connection.

 

 

 

Publication 1761-UM006A-EN-P - February 2001