A 2.1.6 Canopen Over Ethercat; A 2.1.7 Process Data Pdo Mapping; A 2.1.8 Service Data Sdo Service - MICRO-EPSILON combiSENSOR 64x0 Instruction Manual

Appendix| EtherCAT Documentation
A 2.1.6
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 2.1.7
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 combiSENSOR 64x0. The PDO
mapping defines which application objects (measurement data) are transmitted into a PDO. The combiSEN-
SOR 64x0 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
A 2.1.8
Service Data Objects (SDOs) are primarily used for the transmission of data that are not time critical, e.g. pa-
rameter values. EtherCAT specifies the SDO services as well as the SDO information services: SDO services
make possible the read/write access to entries in the CoE object directory of the device. SDO information
services make it possible to read the object directory itself and to access the properties of the objects. All pa-
rameters of the measuring device can be read or changed in this way, or measurements can be transmitted.
A desired parameter is addressed via index and subindex within the object directory.
combiSENSOR 6430
CANopen over EtherCAT
Process Data PDO Mapping
Measurement counter (32 Bit)
Displacement Channel 1
Displacement Channel 2
Displacement Channel 3
Displacement Channel 4
Service Data SDO Service
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