Glossary of EtherCAT terms
EtherCAT, like many other networking systems, has a set of unique terminology. Table below contains a
few of the technical terms used in this guide to describe the EtherCAT interface. They are listed in
alphabetical order.
Acknowledge telegram
(AT)
Telegram, in which each Slave inserts its data.
Actual value
Value of a variable at a given instant.
Algorithm
Completely determined finite sequence of operations by which
the values of the output data can be calculated from the
values of the input data.
Application
Function or data structure for which data is consumed or
produced.
Software functional element specific to the solution of a
problem in industrial-process measurement and control.
Application class
Configuration of a Drive Object with a set of functional
objects and supported by standard telegrams.
Application mode
Type of application that can be requested from a PDS.
Application objects
Multiple object classes that manage and provide a run time
exchange of messages across the network and within the
network device.
Application process
Part of a distributed application on a network, which is located
on one device and unambiguously addressed.
Application relationship
Cooperative association between two or more application-
entity-invocations for the purpose of exchange of information
and coordination of their joint operation. This relationship is
activated either by the exchange of application-protocol-
data-units or as a result of preconfiguration activities.
Attribute
Description of an externally visible characteristic or feature of
an object, property or characteristic of an entity. The attributes
of an object contain information about variable portions of an
object. Typically, they provide status information or govern the
operation of an object. Attributes may also affect the
behaviour of an object. Attributes are divided into class
attributes and instance attributes.
Axis
Logical element inside an automation system (e.g. a motion
control system) that represents some form of movement.
Basic Slave
Slave device that supports only physical addressing of data.
Behaviour
Indication of how an object responds to particular events.
Bit
Unit of information consisting of a 1 or a O. This is the
smallest data unit that can be transmitted.