JVL MAC00-EC41 - Page 37

JVL Industri Elektronik A/S - User Manual - Ethernet for MAC and MIS motors 37
3.2 Protocol specifications
3.2.5 EtherCAT® - State machine
Both the master and the slaves have a state machine with the states shown below. After
boot the slaves are in INIT state, and then it's up to the master to request state transi
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tions. The standardized EtherCAT® state machine is defined in the following figure. The
bootstrap state is not supported.
The module enters the Init state directly after start-up. After this, the module can be
switched to the Pre-Operational state. In the Pre-operational state the EtherCAT® mail
-
box communication is allowed and CoE objects can be accessed by SDOs. After the mas-
ter has configured the slave, it can switch the module to the Safe-Operational state. In
this state input I/O data (PDOs) is sent from the adapter module to the EtherCAT® mas
-
ter, but there is no output I/O data from the master to the module. To communicate out-
put I/O data the master must switch the adapter module to the Operational state.
State description table:
State Description
Init
State after device initialisation. No Application layer communication (no SDO and
PDO communication).
Pre-operational SDO communication possible. No PDO communication.
Safe-operational Transmit PDO operational (drive sends data to master)
Operational Drive fully operational, responds to data via receive PDO
Boot-strap Not used.
Init
Operational
Pre-Operational
Safe-O
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TT3009GB