Lenze E84AYCET EtherCAT MCI module - Manual (Page 57)

Lenze · E84AYCET communication module (EtherCAT) · Communication Manual · DMS 5.0 EN · 05/2013 · TD17
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7 Data transfer
7.3 EtherCAT state machine
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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 and indicated via the BS LED.
Possible errors at the state transitions are shown in C13879 . Additionally, an error message is
entered in the "AL status code" EtherCAT register" ( 58) .
E94AYCET009
Operational
Pre-Operational
Init
Safe-Operational
State Description
Init • Initialisation phase
• No SDO/PDO communication with the slaves
• Device detection possible by means of a 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 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.
• Only in the transitional phases between states can bus nodes be in different states.