Communication - HBM QuantumX CX27C Bedienungsanleitung

EtherCAT
The QuantumX EtherCAT slaves can be configured either via an ESI data set
or by a search function and the EEPROM integrated into the slave. This makes
it possible to read the SM/FMMU information (SYNC Manager/Fieldbus
Memory Management Unit).
6.2.4

Communication

By default, EtherCAT uses CANopen (CoE - CANopen over EtherCAT) as the
application layer.
CANopen (CAN: Controller Area Network) is the open protocol standard for
CAN in automation technology and has been standardized in the "CAN in Au­
tomation" (CiA) association. The protocol uses CAN bus as the transmission
medium and specifies the fundamental structures for network management,
the use of the CAN Identifier (message address), the behavior on the bus over
time, the data transmission types, and application-specific profiles. This is in­
tended to ensure that CANopen modules from different manufacturers can be
combined with each other (that the devices "speak the same language").
CANopen defines the application layer (OSI Layer 7) as the communication
profile specified by the CiA in Standard DS30x as the same for all applications.
It establishes how communication is to take place. As with some other field­
buses, a distinction is also made between real-time data and parameter data.
CANopen uses communication objects with different properties:
Service Data Objects (SDO)
In the parameter channel, all the CX27 parameters can be read and modified
by the SDO service. The required parameter is addressed within an SDO tele­
gram with index and sub-index.
SDOs determine the features of the communication channel for the transmis­
sion of device parameters, for example the sample rate of the A/D converter.
As these parameters are transmitted acyclically (for example, once only, when
turning on the network), SDOs have a subordinate priority.
Process Data Objects (PDOs)
A PDO telegram is used for example to transfer cyclic measured data in real
time. The measured data is used in turn to control, regulate and observe the
running process. The transmission times here are linked to the cycle times/
CX27C 21
A02720_04_X00_00 HBM: public