Ethercat State Machine - YASKAWA SGD7S-1R9D Product Manual

12.2

EtherCAT State Machine

The EtherCAT state machine is used to manage the communications states between the mas-
ter and slave applications when EtherCAT communications are started and during operation, as
shown in the following figure. Normally, the state changes for requests from the master.
Power ON
(OI)
State
INIT
INIT => PRE-OP
PRE-OPERATIONAL
(PREOP)
PREOP => SAFEOP
SAFE-OPERA-
TIONAL
(SAFEOP)
SAFEOP => OP
OPERATIONAL
(OP)
INIT
(PI) (IP)
PRE-OPERATIONAL
(PS) (SP)
(OP) SAFE-OPERATIONAL
(SO)
OPERATIONAL
• Mailbox communications are not possible.
• Process data communications are not possible.
• The master sets the DL address and Sync Manager channels for mailbox communi-
cations.
• The master initializes DC clock synchronization.
• The master requests the Pre-Operational state.
• The master sets the AL control register.
• The slaves check whether the mailbox was initialized correctly.
• Mailbox communications are possible.
• Process data communications are not possible.
• The master sets the Sync Manager channels and FMMU channels for process data.
• The master uses SDOs to set the PDO mappings and the Sync Manager PDO
Assignment parameters.
• The master requests the Safe-Operational state.
• The slaves check whether the Sync Manager channels for process data communi-
cations and, if required, the distributed clock settings are correct.
• Mailbox communications are possible.
• Process data communications are possible. However, only the input data is valid.
The output data is still not valid.
• The master sends valid output data.
• The master requests the Operational state.
• Mailbox communications are possible.
• Process data communications are possible.

12.2 EtherCAT State Machine

(SI)
(OS)
Description
12
12-3