CANopen over EtherCAT (CoE)
CANopen communication objects supported
8
l
18
KHB 13.0005−EN 1.0
8
CANopen over EtherCAT (CoE)
8.1
CANopen communication objects supported
As already described in the previous chapters, the user protocols are tunneled via
EtherCAT. For the CANopen over EtherCAT (CoE) protocol supported by the 931K most
objects for the communication layer are supported by EtherCAT in accordance with the CiA
DS301 standard. These are mostly objects for establishing communication between the
master and the slave.
For the CANopen motion profile in accordance with CiA DSP402 most objects are
supported that can also be operated via the standard CANopen fieldbus. Basically the
following services and object groups are supported by the EtherCAT CoE implementation
in the 931K servo position controller:
Object
Description
SDO
Service Data Object
Are used for the standard parameterisation of the controller.
PDO
Process Data Object
Quick exchange of process data (e.g. actual speed) possible.
EMCY
Emergency Message
Transfer of error messages.
The individual objects that can be addressed via the CoE protocol in the 931K servo position
controller are transferred to the existing CANopen implementation within the controller
and are processed there.
8.2
New communication objects
However, some new CANopen objects were added to the CoE implementation under
EtherCAT, which are required for the specific connection via CoE. This results from the
altered communication interface between the EtherCAT protocol and the CANopen
protocol. There a so−called sync manager is used to control the transmission of PDOs and
SDOs via the two EtherCAT transfer types (mailbox and process data protocol).
Furthermore some CANopen objects of the 931K, which are provided under a standard
CANopen connection, are not supported in the case of a CoE connection via EtherCAT.