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Appendix
118
Product manual | Version: 2.0.0
8DIO FLD EC DC 24V 2.0A
The procedure is as follows:
• The EtherCAT master uses the AoE Read command and writes the ISDU read request
into the AoE mailbox header, indicating the index and subindex. This information ad-
dresses the port and the object of the IO-Link device.
• After the IO-Link device has sent the IO-Link master the response to the ISDU read re-
quest, the EtherCAT slave sends the AoE response to the EtherCAT master.
The following figure shows the process of reading to an IO-Link device with the AoE
Read command:
Figure 41: ISDU Read Process (EtherCAT)
(1) AoE Read Request: Packet Structure for an ISDU Read Request
Addressing is done in AoE via:
• AoE port number (in AoE header)
• IndexGroup (in the AoE data area)
• IndexOffset (in the AoE data area)
The structure of the AoE mailbox frame for transferring the ISDU read request (number
(1) in figure “ISDU Read Process (EtherCAT)”) is as follows:
1. The structure of the AoE mailbox frame corresponds to the description in
8
view of the Structure of the AoE Frame [
2. The AoE header corresponds to the description in
8
.
3. The AoE data area has the following structure for an ISDU read request:
Table 87: Structure of the AoE Data Area for an ISDU Read Request (AoE Read Request)
Offset
Parametername
Type
Value
Description
0
IndexGroup
Unsigned32
0xF302
IndexGroup of the data to be read (fixed
value).
4
IndexOffset
Unsigned32
see below IndexOffset of the data to be read. Contains
index and subindex of the IO-Link object.
Structured according to the following table.
8
Length
Unsigned32
–
Length of the data to be read (in bytes)
The data is stored in Index Offset as follows:
Table 88: Structure of the IndexOffset in the AoE Data Area for an ISDU Read Request (AoE Read Request)
Offset
Parametername
Type
Value
Description
4
(IO-Link index)
Unsigned16
0x0000 ...
0x7FFF
Object index of the IO-Link device to be
read from.
6
–
Unsigned8
0x00
Fixed value
7
(IO-Link subindex)
Unsigned8
[0x00...0x
FF]
Object subindex of the IO-Link device to be
read from.