State Machine

EtherCAT state machine

Figure 5-61: EtherCAT State Machine

Where the transitions are:

from Init to Pre-Operational (Pre-Op): Master configures the Sync Manager channels for Mailbox communication
from Pre-Op to Safe-Operational (Safe-Op): Master configures parameter using the Mailbox
from Safe-Op to Operational (Op): Master sends valid Outputs

The different states are:

Init
No communication on the Application Layer
Master has access to the DL-Information registers
Pre-Operational (Pre-Op)
Mailbox communication on the Application Layer
No Process Data communication
Safe-Operational (Safe-Op)
Mailbox communication on the Application Layer
Process Data communication. Only Inputs are evaluated (Outputs in Safe state)
Operational (Op)
Inputs and Outputs are valid
Bootstrap
Recommended if firmware updates are necessary
No Process Data communication
Communication via Mailbox on Application Layer
Only FoE protocol available