NORD Drivesystems BU0270 - Manual (Page 34)

Supplementary Manual EtherCAT for NORDAC SK 200E
34 Subject to technical amendments BU 0270 GB
5 EtherCAT data transmission
EtherCAT communication is based on the single master principle. Although the bus modules can communicate
from "Slave to Slave" in the process data channel, and therefore two or more devices can be coupled together,
an EtherCAT master is always required for this function.
5.1 NMT State Machine
The NMT State Machine defines various communication states of the SK TU4-ECT. The switchover between
the individual states is made via the SPS (EtherCAT Master).
The slave can only independently exit from the "Operational" state in case of severe communication errors at
the EtherCAT level.
State Explanation
Init No communication of process data and parameters
Pre-Operational - Communication of parameters
- No process data communication
Save Operational - Communication of parameters
- Restricted process data communication (only actual values are transmitted, setpoint are not evaluated)
Operational - Communication of parameters
- Unrestricted process data communication
Init
Pre-Operational
Save Operational
Operational
NMT State Machine
Explanation of NMT States