EtherCAT State Machine

EtherCAT state machine

Figure 6-63: 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

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