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5
Fundamentals of EtherCAT
ID 441896.05
WE KEEP THINGS MOVING
Operation manual
20
A PLC usually performs the startup in this sequence of states:
Initialising - Pre-Operational - Safe-Operational - Operational
If, for example, the TwinCAT
®
software from Beckhoff Automation GmbH is used,
these steps can be executed automatically by the System Manager or individually
as needed. When a controller program is started on the TwinCAT
®
PLC, the
startup is executed automatically.
OI
Stop output update, stop input update, stop mailbox
communication
Transition
Actions