8 EtherCAT communication
8.1
EtherCAT State Machine
The EtherCAT State Machine in Figure 8-1 indicates which functionalities are actually available.
The functions in the different states are described in Table 8-1below. Transitions among states are
described in Table 8-2.
Figure 8-1 EtherCAT Slave State Machine
State
Description
INIT
Init state
No communication on the application layer is available.
The master has access only to the DL-information registers
PREOP
Pre-Operational state
Mailbox communication on the application layer available, but no
process data communication available. Master setup cyclic
communication via PDOs
SAFEOP
Safe-Operational state
Mailbox communication on the application layer, process (input) data
communication available.
In SafeOp only inputs are evaluated; outputs are kept in ‘safe’ state.
OP
Operational state
Process data inputs and outputs are valid.
BOOT
Bootstrap state
No process data communication.
Communication only via mailbox on Application Layer available.
Used for firmware updates.
Table 8-1 EtherCAT State Machine Description
Transition
Description
I -> P
Master reads VendorID, ProductCode and RevisionNumber from
EEPROM, and configures DL registers, SyncManager registers for
mailbox communication and initialize DC clock synchronization.
Master requests PreOp state and waits for status confirmation.
HT7 Ethercat User Guide
15
Summary of Contents for EtherCAT HT7
Page 76: ...www shsitalia it info shsbox shsitalia it 15 ...
Page 91: ...www shsitalia it info shsbox shsitalia it 2 5 Digital Inputs 2 6 Digital Outputs 14 ...
Page 92: ...www shsitalia it info shsbox shsitalia it 2 7 Encoder Inputs 15 ...
Page 95: ...www shsitalia it info shsbox shsitalia it 18 ...
Page 110: ...www shsitalia it info shsbox shsitalia it 2 5 Digital Inputs 2 6 Digital Outputs 14 ...
Page 111: ...www shsitalia it info shsbox shsitalia it 2 7 Encoder Inputs 15 ...
Page 124: ...www shsitalia it info shsbox shsitalia it 28 ...