BECKHOFF CX2100­09x4 - Manual (Page 23)

Product overview
Init
After switch­on the EtherCAT slave in the Init state. No mailbox or process data communication is possible.
The EtherCAT master initializes sync manager channels 0 and 1 for mailbox communication.
Pre­Operational (Pre­Op)
During the transition from Init to Pre­Op, the EtherCAT slave checks whether the mailbox has been correctly
initialized. Mailbox communication is possible in the Pre­Op state, but no process data communication. The
EtherCAT master initializes the sync manager channels for process data (from sync manager channel 2), the
FMMU channels and, if the slave supports configurable mapping, PDO mapping or the sync manager PDO
assignment. In this state the settings for the process data transfer and perhaps terminal­specific parameters
that may differ from the default settings are also transferred.
Safe­Operational (Safe­Op)
During transition between Pre­Op and Safe­Op the EtherCAT slave checks whether the sync manager
channels for process data communication and, if required, the distributed clocks settings are correct. Before
it acknowledges the change of state, the EtherCAT slave copies current input data into the associated DP­
RAM areas of the EtherCAT slave controller (ECSC).
Mailbox and process data communication are possible in the Safe­OP state; however, the slave maintains its
outputs in the safe state and does not output them. The input data, however, are already cyclically updated.
Operational (Op)
Before the EtherCAT master switches the EtherCAT Slave from Safe­Op to Op, it must transmit already valid
output data. In the Op state the slave copies the output data of the master to its outputs. Process data and
mailbox communication is possible.
Boot
In the Boot state the slave firmware can be updated. The Boot state can only be reached via the Init state. In
the Boot state mailbox communication is possible via the File­Access over EtherCAT (FoE) protocol, but no
other mailbox communication and no process data communication is possible.
CX2100­09x4 23 Version 1.1