ABB FENA-01, User Manual

Page: 151 / 388

EtherNet/IP – Start-up 151
Select connection method
EtherNet/IP provides a variety of connection methods to
communicate between devices. Not all methods are supported by
all devices. Refer to the client documentation to determine which
method(s) are supported by the client.
Note: The choice of the connection method has a significant
impact on the timeout behavior. Refer to configuration parameters
20 CONTROL TIMEOUT and 21 IDLE ACTION for more
information.
The FENA adapter module supports the following connection
methods:
I/O connections
The adapter module supports Class 1 I/O connections. I/O
connections are often also referred to as “Implicit Messaging”. I/O
connections are typically established by configuring an I/O scanner
to write and read assembly object instances.
Connected explicit messaging
The adapter module supports Class 3 connected explicit
messaging. Class 3 connected explicit messages are typically
established by using a “message instruction” to write or read an
attribute.
Note: When using Class 3 explicit messaging, some EtherNet/IP
clients may close the connection after the MSG instruction is done.
This will cause the module to behave as if it were controlled via
unconnected explicit messaging.
Unconnected explicit messaging
The adapter module supports unconnected explicit messaging.
Unconnected explicit messages are typically established by using
a “message instruction” to write or read an attribute.
Note: EtherNet/IP does not provide a timeout means for
unconnected explicit messaging. To use unconnected explicit
messaging for control, refer to configuration parameter 20
CONTROL TIMEOUT .