Rockwell Automation Ethernet Design Considerations Reference Manual User Manual
Page 60
60
Rockwell Automation Publication ENET-RM002C-EN-P - May 2013
Chapter 4
EtherNet/IP Protocol
This graphic shows how connections are layered on each other when data is
transferred over the EtherNet/IP network.
Remember these points when configuring your EtherNet/IP network
application:
•
All of the connections are used each time data is transferred on the
EtherNet/IP network.
•
You specify CIP connection message types and CIP connection types
when configuring your application.
For example, when a Logix5000 controller sends a MSG instruction to
another Logix5000 controller, the transmitter sends the instruction to the
receiver over a connection. That connection includes the following:
–
A TCP connection is established.
–
A CIP connection is layered on the TCP connection.
–
An explicit or implicit CIP connection message is delivered via the CIP
connection.
–
If an explicit message type is used, it can be connected or unconnected.
If an implicit message type is used, it is connected.
•
Each EtherNet/IP communication module has TCP and CIP connection
limits that you must account for when configuring your application. For
more information on connection limits, see
Table 12 on page 66
.
•
Nodes on an EtherNet/IP Network on page 65
for node count
limitations for CompactLogix 5370 controllers.
TCP Connection
CIP Connection
Explicit
Implicit
CIP Connection Message Types
Connected
Connected
CIP Connection Types
Unconnected
You do not execute any tasks to
establish these connections.
Your decisions when configuring
your application determine the
parameters of these connections.