Stober SC6 Series, Руководство по эксплуатации

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9 | Looking for more information about EtherCAT? STOBER
54
02/2020 | ID 443025.06
9.3.1.1 PDO mapping
In PDO mapping, the communication parameters to be transmitted are mapped to PDOs and the associated transmission
channel. This determines which communication objects are transferred over the process data channel.
The STOBER drive controllers support a flexible assignment of the elements to be transmitted to the individual PDOs. PDO
communication allows for a maximum of four independent PDO channels to be operated simultaneously per transmission
and sending direction, where channel 4 is a safety channel.
Each of these PDO channels includes a PDO with a defined sequence of up to 24 parameters to be exchanged (the number
of parameters depends on the drive controller type). In order to guarantee error-free communication between the
controller and drive controller, STOBER offers application-dependent, proven pre-assignment of the channels in
DriveControlSuite which can be changed at any time.
9.3.2 Service data objects – SDO
Service data objects are used to transmit data that is not time-critical. They enable read and write access to the
configuration parameters of an EtherCAT slave.
SDO frames are transmitted over the mailbox channel acyclically during ongoing cyclical EtherCAT operation, without
impairing PDO communication.
9.3.2.1 Addressing axis-dependent parameters
When addressing axis-specific parameters of physical axes using SDOs, the parameters are addressed directly in accordance
with the access rules described in the appendix (see the chapters
Manufacturer-specific parameters: 2000 hex – 53FF hex
[
}
77] and Manufacturer-specific parameters: A000 hex – D3FF hex [
}
81] ).
9.3.2.2 Expedited transfer
The simplified, expedited SDO transfer is used for transferring all parameters with a data type of maximum of 4 bytes. In
this type of transmission, 4 data bytes are sent in a single frame. The data is arranged in accordance with the Intel format
(little-endian), meaning that the byte with the smallest value is saved at the starting address and transmitted first (compare
with big-endian or Motorola format, where the highest-value component is sent first).
Write parameter (Initiate Domain Download Request)
The master uses an Initiate Domain Download Request to initiate a write process for a communication parameter. The
request receives a positive acknowledgement from an Initiate Domain Download Response of the slave.
Byte 1 2 3 6 5 4 7 8
0x23 LSB MSB MSB LSB LSB MSB
Master Slave
Command Index
Sub-
index
LSW data MSW data
Byte 1 2 3 6 5 4 7 8
0x63 LSB MSB MSB LSB LSB MSB
Command Index
Sub-
index
Unused