11
Series 70
Servo NXT - EtherNet/IP
Installation, Operation and Maintenance Manual
will automatically attempt to gain a lease for an
available IP address.
If the Servo NXT EIP is going to be connected
to a network that uses static addressing, then a
scanner will have to be connected to the Servo
NXT EIP to adjust the default settings of the TCP/
IP object to make the device use the address
stored in memory and, if necessary, change the
address to one conformant to the network’s
requirements.
5.4 Establish Connection
Once an IP address has been assigned to the
Servo NXT EIP, a Class 3 explicit connection can
be established that allows for class and instance
attribute data to be read and written. An explicit
connection has the benefit of being reliable and
connection oriented where every message sent is
verified. However, there is a significant amount
of overhead associated with requiring every
message to be verified. Explicit messaging is used
for establishing implicit message generation,
but once this is accomplished, it should be used
sparingly to reduce the occurrence of collisions.
Once a Class 3 connection has been established
with the Servo NXT EIP, Class 1 implicit messages
should be configured based on the Connection
Manager attributes defined in the EDS file. The
EDS file provides limits for implicit messaging
to ensure the device maintains reliable
generation of data. Since implicit messaging is
connectionless, there is no need to establish,
maintain, or terminate a session. Once message
generation is started, it continues based on
the RPI defined by the scanner, and it does not
require the presence of the scanner to occur.
The implicit data generated from the Servo NXT
EIP originates from the Assembly Object data
attributes. There are three Assembly Objects
available:
• Input Assembly – Servo NXT EIP data array
that is generated for consumption by the
network scanner, containing data relevant
to the device’s current operation, such as
feedback position.
• Output Assembly – Data array sent to
the Servo NXT EIP to affect its operation,
containing data that changes how the device
is operating, such as command position.
• Configuration Assembly – Data array sent to
the Servo NXT EIP that defines the operating
conditions and limits of the device. This array
is only sent at the initiation of an implicit
connection and can therefore not be changed
once messaging starts unless message
generation is halted.
Since Assembly data is application specific, the
following sections contain detailed information
on the Assembly Object data present in the
Servo NXT EIP.
