turck BL20 - Parameterization through Service Data Objects (SDO)

BL20 - Communication in CANopen
D301087 0308 - BL20 CANopen4-16
Parameterization through Service Data Objects (SDO)
SDO (= Service Data Object) is a confirmed CANopen service that is
primarily used for parameterization and configuration of the
CANopen slaves (BL20) and less frequently for transmitting process
data. "Confirmed" means that an BL20-CANopen gateway (SDO
server) that is addressed by this procedure must acknowledge it
through a response. In this way, the SDO client obtains information
about whether the BL20 gateway that it addressed was contacted,
and whether the access was achieved without any errors (error code
in the response from the SDO server). SDO access means that the
contents of the Object Dictionary entries for an SDO server can be
read or written, and that the settings for a BL20 station can be made
in this way.
Four parallel SDO servers are supported. There are three "addi-
tional" SDOs, as well as the default SDO. As a default, these are
inactive, but can be parameterized and enabled through the Object
Dictionary entries 1201
hex
to 1203
hex
.
The communication parameters for the default SDO follow the
Predefined Connection Set, and cannot be modified (see CiA DS-
301, V4.01)
In the following representations of the messages, the identifier of the
CANopen message that is to be sent can be found below the frame,
and the contents of the data byte to be transmitted are within the
frame.
The following representations use the Expedited SDO Transfer, i.e.
a maximum of 4 bytes of user data can be transferred within one
telegram.
Note
CANopen also offers the possibility of segmented SDO-transfer of
data with data length of more than 4 bytes.