1-3
Introduction to Communications
Services
This section provides an introduction to the communications services of the NX-series EtherNet/IP
Unit.
1-3-1
CIP (Common Industrial Protocol) Communications Services
The services using CIP include tag data link and CIP message communications.
Tag Data Links (Cyclic Communications)
A program is not required to perform cyclic data exchanges with other devices on the EtherNet/IP net-
work.
Normally, a connection is started with the target device for each tag set that was created with the Net-
work Configurator to start communications for tag data links for an EtherNet/IP port. One connection is
used per tag set.
The maximum number of connections that can be registered is 256, or a total of 512 with two ports.
Additional Information
The NX502 CPU Unit can be used with the NX-EIP201 (EherNet/IP Unit) for tag data link com-
munications.
However, check the effect on task execution time because it increases I/O refreshing time.
Refer to 2-1 Specifications on page 2-2 for the EtherNet/IP port tag and tag set specifications.
EtherNet/IP
Tag ii
Originator device Target device
Tag i
Controller Status
Tag set name: SP1_OUT
Tag Set (Output)
Data flow
Connection
Tag g
Tag c
Tag b
Tag a
Controller status
Tag set name: SP1_IN
Tag Set (Input)
• Packet interval (RPI)
• Originator tag set
• Target tag set
• Target IP address
Connection Information
1 Features and System Configuration
1-8
NX-series EtherNet/IP Unit User's Manual (W627)