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Rockwell Automation Publication 1769-UM021G-EN-P - October 2015
Chapter 6
Communicate over Networks
EtherNet/IP Network Connections
CompactLogix 5370 controllers use connections to manage communication on
the EtherNet/IP network. A connection is a point-to-point communication
mechanism that is used to transfer data between a transmitter and a receiver.
Connections can be logical or physical.
You indirectly determine the number of connections the controller uses by
configuring the controller to communicate with other devices in the system.
Connections are allocations of resources that provide more reliable
communication between devices than unconnected messages.
All EtherNet/IP connections are unscheduled. An unscheduled connection is a
message transfer between controllers that the requested packet interval (RPI) or
the program, such as a MSG instruction, triggers. Unscheduled messaging lets
you send and receive data when needed.
This table lists information for CompactLogix 5370 controllers.
Table 5 - CompactLogix 5370 Controller EtherNet/IP Network Port Specifications
Cat. No.
Connections
CIP
Unconnected
Messages
(bac
Ethernet)
Packet Rate Capacity
(packets/second)
(1)
SNMP
Support
(password
required)
Media
Support
Produced/Consumed Tags
Controller
TCP
CIP
I/O
HMI/MSG
Number of
Multicast
Tags,
max
(2)
Unicast
Available
1769-L16ER-BB1B
256
120
256
256
6000 @ 500
bytes/
packet
400
messages/s
@ 20%
comm.
timeslice
Yes
Twisted Pair
32 multicast
produced
tags
128 unicast
produced
tags
Yes
1769-L18ER-BB1B
1769-L18ERM-BB1B
1769-L24ER-QB1B
1769-L19ER-BB1B
1769-L24ER-QBFC1B
1769-L27ERM-QBFC1B
1769-L30ER
1769-L30ERM
1769-L30ER-NSE
1769-L33ER
1769-L33ERM
1769-L36ERM
(1) Total packet rate capacity = I/O Produced Tag, max + HMI/MSG, max Packet rates vary depending on packet size. For more detailed specifications, see the capacity section of the EDS file for the catalog
number.
(2) These are the maximum numbers of CIP I/O connections.
