Delta RMC151 - Manual (Page 464)

RMC70/150 and RMCTools User Manual
EtherNet/IP I/O
EtherNet/IP I/O provides a mechanism of deterministically sending data in both directions
between a PLC and remote device. This data is sent on an interval called the Requested
Packet Interval (RPI). The RMC supports a minimum RPI of 2.0 ms to 4.0 ms, depending
on the loop time and number of connections.
EtherNet/IP I/O is a very fast and easy-to-use method of communication. It reduces the
amount of ladder logic required for communication, and communication occurs even when
the PLC is in Program mode.
The RMC supports up to 4 simultaneous EtherNet/IP I/O connections. Only one
connection can be a controlling connection. A controlling connection sends and receives
data with the RMC using the producer-consumer model. The remaining connections must
be input-only, which can only receive data from the RMC. Input-only connections are
rarely used.
The RMC supports only one controlling I/O connection at a time. Therefore, EtherNet/IP
I/O cannot be used simultaneously with a PROFINET IO connection. Other protocols can
be used simultaneously with EthetNet/IP.
EtherNet/IP I/O requires firmware version 2.20 or later.
To learn about setting up and using EtherNet/IP I/O, see the following topics:
• Using Allen-Bradley Controllers via EtherNet/IP I/O
• Using Omron Controllers via EtherNet/IP I/O
• Setting up an EtherNet/IP I/O Connection
• Using an EtherNet/IP I/O Connection
EtherNet/IP Messaging
EtherNet/IP explicit messaging allows the originator (PLC or HMI) to request individual
services from the target device (RMC). These requests are made explicitly rather than
being scheduled cyclically like I/O. Explicit messaging is much more flexible than I/O in
terms of what data or services are accessed in the target device, since I/O connections
must pre-configure the I/O data to be exchanged.
In most cases, RMC users use EtherNet/IP Explicit messaging to read and write registers
in the RMC. The RMC provides two methods for doing so. Also, some advanced
EtherNet/IP users may want to access standard CIP services and attributes.
The three types of EtherNet/IP explicit messaging services users may want to use in the
RMC are:
• Read and/or write RMC registers using the Allen-Bradley PCCC/DF1 services.
• Read and/or write RMC registers using the Data Table Object.
• Access standard CIP services and attributes.
See Using EtherNet/IP Explicit Messaging for details on all three.
Supported Number of Connections
The maximum number of each type of connection supported by the RMC75E and
RMC150E is listed below:
Connection Type Maximum
TCP 64
CIP 32
CIP I/O 4*
*Only one CIP connection can have output data sent from the PLC. The rest must be
Input Only or Listen Only.
444 Delta Computer Systems, Inc.