Datalogic AMT58*-PN Series Instruction Manual page 11

PROFINET IO, 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
PROFINET IO interface. Sometimes they also refer more specifically to the S7
programming environment. They are listed in alphabetical order.
Acyclic
Communications
AP
API
Application class
AR
Bus
Channel
Consumer Status The Status an IO device provides to an IO Controller for the data it
CR
Cyclic
Communications
Data block
DCP
Glossary of Profinet terms
Unscheduled, on demand communications. Diagnostic messages from
an IO Supervisor to an IO Device are Acyclic. Refer to page 58.
Application Process - The application process running in the device.
PROFINET supports a default Application Processes and additional
profile specific application processes.
The value of the API (Application Process Identifier) parameter
specifies the application that is processing the IO data. PROFINET
standard IEC 61158 assigns profiles to certain APIs (PROFIdrive,
PROFIslave) which are defined by the PROFINET User Organization.
The standard API is 0.
An application class specifies a number of mandatory functions and
addition optional functions to be supported by an IO device. The
Profinet encoders can be configured as CLASS 3 and CLASS 4
PROFINET IO devices according to the encoder profile. Refer to page
41
Application Relation - The relationship between a PROFINET IO
Controller and an IO device. A PROFINET IO device can support more
than one Application Relationship.
A bus is a communication medium connecting several nodes. Data
can be transferred via serial or parallel circuits, that is, via electrical
conductors or fiber optic.
A single IO point. A Channel can be discrete or analog.
consumes from IO Controller.
Communication Relationship - A virtual communication channel within
an AR.
Scheduled, repetitive communications. IO data and alarm transfers are
cyclic.
In contrast to code blocks, data blocks (DB) do not contain Step 7
statements. They are used to save data, i.e. variable data which are
processed by the user program. Global data blocks serve to
accommodate user data which can be used by all other blocks.
Discovery Control Protocol - A communications protocol with
PROFINET IO that allows an IO Controller or Supervisor to find every
PROFINET IO device on a subnet.