Glossary
STOBER
90
02/2020 | ID 442516.07
PDO
Communication objects in a CANopen or EtherCAT network that transmit data such as set and actual values, control
commands or status information based on events or objectives, in cycles or in real time on request. PDOs are generally
exchanged over the process data channel with high priority. Depending on the view of the respective node, a
distinction is made between receive PDOs (RxPDO) and transmit PDOs (TxPDO).
SDO
Communication objects in a CANopen or EtherCAT network that grant access to the object directory and enable device
configuration. SDOs are transmitted over the mailbox channel acyclically during ongoing cyclical CANopen or EtherCAT
operation.
SM-Sync
Also: Synchronization using SyncManager event. Method for EtherCAT network synchronization where the EtherCAT
slaves synchronize with an event from incoming data.
Synchronization
Time adjustment of EtherCAT network nodes that allows the EtherCAT master and slaves to work synchronously with
each other in the same cycle. EtherCAT provides two different methods for precisely synchronizing the master and
slaves: a SyncManager event (SM-Sync) and distributed clocks (DC-Sync). The FreeRun state exists if the master and
slaves are not synchronized.