Communications State Transitions - Omron GX-ID1611 User Manual

5 EtherCAT Communications
5-3

Communications State Transitions

The EtherCAT State Machine (ESM) indicates the state transition model of EtherCAT Slave Unit
communications control. It is controlled by EtherCAT Master Unit.
The following figure shows the communications state transitions from power ON.
State
Initialization (Init)
Pre-Operational
(Pre-Op)
Safe-Operational
(Safe-Op)
Operational (Op)
5 - 4
Power ON
Initialization
Pre-Operational
Safe-Operational
Operational
SDO PDO
communi transmiss
cations ion
Not Not
possible. possible.
Not
Possible
possible.
Possible Possible
Possible Possible
PDO
reception
Not Communications are being initialized.
possible. Communications are not possible.
SDO (message) communications are
possible in this state.
Not
This state is entered after initialization has
possible.
been completed. It is used to initialize
network settings.
In this state, PDO transmissions are possible
in addition to SDO (message)
Not communications.
possible. PDO sendings can be used to send
information such as status from the Slave
Unit.
Normal communication state
Possible PDO communications can be used to control
the I/O data.
GX-series EtherCAT Slave Unit User's Manual
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