Lenze · E94AYCET communication module (EtherCAT®) · Communication Manual · DMS 10.2 EN · 11/2018 · TD06 59
7 Data transfer
7.3 EtherCAT state machine
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
7.3 EtherCAT state machine
Before communication is possible via EtherCAT, the fieldbus passes through the EtherCAT state
machine during start-up. The following illustration depicts the possible state changes from the
point of view of an EtherCAT slave:
[7-1] EtherCAT state machine
The current status of the EtherCAT state machine is shown in C13861 / C14861 and is indicated via
the RUN LED.
E94AYCET009
Operational
Pre-Operational
Init
Safe-Operational
Status Description
Init • Initialisation phase
• No SDO/PDO communication with the slaves
• Device can be detected by fieldbus scan
Pre-Operational • The fieldbus is active.
• SDO communication (mailbox communication) is possible.
• No PDO communication
Safe-operational • SDO communication (mailbox communication) is possible.
• PDO communication:
• The input data in the process image are updated.
• The output data from the process image are not transferred to the slaves.
Operational Normal operation:
• SDO communication
• PDO communication
• Fieldbus synchronisation has been successful (if used)
Note!
• A fieldbus scan can be carried out during any EtherCAT status.
• SDO communication via the EtherCAT bus is only possible if at least the "Pre-
Operational" state has been reached.
To Next Page
Loading...
