GE Industrial Solutions AF-650 GP PROFINET - Manual (Page 34)

7 PROFINET Acyclic Communication
PROFINET offers additional to the cyclical data communi-
cation, an cyclical communication. This feature is possible
by an IO controller (e.g. PLC), as well as an IO Supervisor
(e.g. PC Tool).
Cyclical communication means that data transfer takes
place all the time with a certain update rate. This is the
known function normally used for quick update of I/O
Process Data. A-cyclical communication means a one time
event, mainly used for Read/Write on parameters from
Process controllers, PC based tools or monitoring systems.
7.1.1 Features of an IO Controller System
- Cyclical data exchange.
- A-cyclical read/write on parameters.
The a-cyclical connection is fixed and can not be changed
during operation.
In general an IO controller is used as Process controller,
responsible for commands, speed reference, status of the
application etc. ( PLC or PC based controller.)
The IO controller, a-cyclical connection might be used for
general parameter access in the slaves.
7.1.2 Features of an IO-Supervisor System
- Initiate/Abort a-cyclical connection.
- A-cyclical read/write on parameters.
The a-cyclical connection can be established dynamically
(Initiate) or removed (Abort) even though an IO controller
is active on the network.
The a-cyclical connection is typically used for configuration
or commissioning tools for easy access to each parameter
in any slave in the system.
PROFINET Acyclic Communicat... PROFINET Operating Instruction
33
7 7