Data transmission with PDO and SDO
Operation manual
ID 441896.05
WE KEEP THINGS MOVING
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Data transmission with PDO and SDO
As the exchange of effective data represents the essential task of an EtherCAT
system, the description begins with the PDO and SDO communication services.
SDO
All parameter of the inverter can be read and changed in the parameter channel
by the SDO service (SDO = Service Data Object). The desired parameter
(communication object) is addressed within an SDO telegram by the index and
subindex.
PDO
A PDO telegram (PDO = Process Data Object) is used to transfer data that is
used to control and monitor the ongoing process and for which a short transfer
time is required. No objects are addressed in the telegram. Instead the contents
of the previously selected parameters are sent directly.
Drive controller with EtherCAT accessories
Set of all
communication objects
Parameter, Indications
(act. values), control
commands, Reference
values, actions
Parameter channel
SDO(tx)
SDO(rx)
Set of all "mappable“
communication objects
Parameters identified
with "PDO“
PDO(rx)
PDO(tx)
Drive controller with EtherCAT accessories
Parameter channel
