Rockwell Automation 1761-NET-ENIW MicroLogix Ethernet Interface (ENI) User Manual - Manual (Page 31)

1 Publication 1761-UM006E-EN-P - August 2005
Chapter
3
Operation
This chapter describes ENI/ENIW operation. The following
information is included:
• Operation Overview
• Allocation of Ethernet Connections
• ENI and ENIW Functional Overview
• General Ethernet Information
• RSLinx/RSWho Connectivity Example Using ENI/ENIW Interface
Operation Overview Ethernet is the protocol used to transport TCP/IP messages. On top of
TCP, EtherNet/IP is the open protocol used by the ENI and ENIW.
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.
Allocation of Ethernet
Connections The ENI and ENIW support 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.