Explicit Message Communications - Omron NXEIP202 User Manual

more than one EtherNet/IP master. For an EtherNet/IP Coupler Unit, a connection I/O type of
input/output is equivalent to an exclusive owner connection.
 Input Only Connection
An input only connection is used to connect to an EtherNet/IP slave that has input data so that the
input data can be received from the EtherNet/IP slave. You can create input only connections from
more than one EtherNet/IP master. With an input only connection, the master device produces only
a heartbeat signal to the EtherNet/IP slave and no output data is present.
 Listen Only Connection
A listen only connection is like an input only connection in that it is used to receive input data from an
EtherNet/IP slave. A listen only connection can be attached to an existing exclusive owner or input
only connection opened by another EtherNet/IP master, but only when multicasting is specified for
sending the input data to EtherNet/IP masters. A listen only connection cannot be created if there is
no existing connection or if the input data send specification to the EtherNet/IP master is not for mul-
ticasting. If the existing connection closes, then the listen only connection will also be closed or
timed out.
8-1-2

Explicit Message Communications

The EtherNet/IP Coupler Unit supports explicit message server functions to access CIP objects from a
device such as an EtherNet/IP master or configuration tool. You can use explicit messages to access
CIP objects to read current error information, clear current errors, read event logs, and use other trou-
bleshooting functions and to set the Unit operation settings, the IP address setting, or other communi-
cations parameters. Also, if the EtherNet/IP master does not support tag data links (i.e., implicit
messages), you can use explicit messages as an alternative message means to control I/O for Ether-
Net/IP Slave Terminals. Refer to A-1 Supported CIP Objects on page A-3 for details on CIP objects that
are supported by the EtherNet/IP Coupler Unit. Refer to A-3 Examples of EtherNet/IP Slave Terminal
Settings and I/O Data Control Procedure Using Messages on page A-45 for specific procedures.
NX-series EtherNet/IP Coupler Unit User's Manual (W536)
8 EtherNet/IP Communications
8
8 - 3