Revision April, 2015
3-1
Chapter 3
EtherCAT
Communication States
ASDA A2-E supports four EtherCAT communication states which are shown as below:
Init
(Initialization)
Pre-Operational
Safe-Operational
Operational
Init
Pre-operational
Safe-operational
Operational
(OI)
(IP)
(PI)
(OP)
(PS)
(SP)
(SO)
(OS)
(SI)
Figure 29 The EtherCAT State machine
EtherCAT host controller can switch the states. Different state provides different
service.
State
Description
Init
After power on, the system will be located in this state when hardware
is initialized without any error.
No communication packet is sent at this stage.
Pre-Operational
The mailbox can be accessed via SDO (Service Data Object).
The Emergency message will be sent to the host controller if any
alarm occurs.