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ICC
8.7.5
EtherNet/IP Client
The EtherNet/IP client protocol can be used to access information on EtherNet/IP
and CSP server devices which support class 1 I/O messaging and class 3 explicit
messaging. Similar to other master/client protocol drivers on the gateway, the
EtherNet/IP client driver uses service objects to produce and consume data and
to issue explicit read and write requests to the server device. EtherNet/IP service
objects also make use of an additional gateway construct called a connection
object in order to target server devices. A connection object can be thought of as
a communication channel or “pipe” which is created between the gateway and the
server device, independent of the service objects that may later make use of that
communication channel to transfer service object requests.
A connection object defines a connection to a specific endpoint (IP address). For
each connection object, however, up to two underlying EtherNet/IP client
connections can be simultaneously established: one connection is reserved for
class 1 I/O messaging and the other connection is reserved for class 3 explicit
messaging. The class 3 explicit messaging connection is capable of managing
any number of service objects targeting the remote endpoint defined by the
connection object (the service objects are serviced sequentially). Several
different types of class 3 requests are available to match the capabilities of a
variety of EtherNet/IP server devices.
Only class 3 connections can be used when connecting to CSP server devices
(such as PLC-5/E or SLC-5/05 PLCs, etc.), as these devices do not support class
1 data transfers. Additionally, not all EtherNet/IP server devices support both
class 1 and class 3 connections: please confirm the capabilities of the targeted
server device when configuring the gateway’s service objects.
Because service objects must always be configured to use a specific connection
object, at least one connection object must initially be created before any service
objects can be created. For more information on service objects, refer to section
8.5.
To configure the EtherNet/IP client, click on the
Ethernet Configuration
tab,
check
EtherNet/IP Client
in the protocol dropdown menu to enable the driver,
and then click on the
EtherNet/IP Client
subtab. This section will discuss how to
configure the EtherNet/IP client.
Explicit Messaging Scan Rate
This is the time in milliseconds the device will wait between sending class 3
explicit messaging requests. If no additional time is required, set this field to 0.
8.7.5.1
Connection Object Configuration Group
Up to 4 connection objects can be created.
