A 6.1.6 Canopen Over Ethercat; A 6.1.8 Service Data Sdo Service; A 6.2 Coe - Object Directory - MICRO-EPSILON capaNCDT 6228 Operating Instructions Manual

Appendix| EtherCAT Documentation

A 6.1.6 CANopen over EtherCAT

The application level communication protocol in EtherCAT is based on the communication profile CANopen
DS 301 and is designated either as "CANopen over EtherCAT" or CoE. The protocol specifies the object
directory in the sensor, as well as the communication objects for the exchange of process data and acyclic
messages. The sensor uses the following message types:
- Process Data Object (PDO). The PDO is used for the cyclic I/O communication, therefore for process data.
- Service Data Object (SDO). The SDO is used for acyclic data transmission.
The object directory is described in the chapter CoE Object Directory.
A 6.1.7 Process Data PDO Mapping
Process Data Objects (PDOs) are used for the exchange of time-critical process data between master and
slaves. Tx PDOs are used for the transmission of data from the slaves to the master (inputs), Rx PDOs are
used to transmit data from the master to the slaves (outputs); not used in the capaNCDT 62x8. The PDO
mapping defines which application objects (measurement data) are transmitted into a PDO. The ca-
paNCDT 62x8 has a Tx PDO for the measuring data. The following measurements are available as process
data:
- Counter
- Channel 1
- Channel 2
- Channel 3
- Channel 4
capaNCDT 6228 / 6238
Measurement counter (32 Bit)
Displacement Channel 1
Displacement Channel 2
Displacement Channel 3
Displacement Channel 4
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