ABB RECA-01, User Manual

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Communication
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Figure 7. EtherCAT® state machine
The EtherCAT® module enters the INIT state directly after start-
up. After this, the module can be switched to the PRE-OP state. In
the PRE-OP state EtherCAT® mailbox communication is allowed
and drive parameters can be accessed by CoE SDOs.
After the master has configured the slave it can switch the module
to state SAFE-OP. In this state input I/O data (PDOs) is sent from
the module to the EtherCAT® master, but there is no output I/O
data from the master to the module.
In order to communicate Output I/O data the master must switch
the module to the OP state.
CANopen over EtherCAT® (CoE)
The application layer communication protocol in EtherCAT® is
based on the CANopen DS 301 communication profile and is
called CANopen over EtherCAT, or CoE. The protocol specifies
the Object Dictionary in the module, as well as communication
objects for exchanging process data and acyclic messages.
RECA-01 implements the following message types: