ADS
Communication relating to IO-Link demand data is initiated via an ADS command. An ADS address always consists of a NetID and PortNo. An ADS command is forwarded from TwinCAT to the ED/EJ/EL6224-00x0 via AoE (ADS over EtherCAT). From there, the command is relayed to the IO-Link master section and therefore to the demand data channel.
AoE NetID
The ED/EJ/EL6224-00x0 is assigned a dedicated AoE-NetID for communication with the IO-Link master section. This is assigned by the configuration tool (see the following figure).
NetID at “ED/EJ/EL6224-00x0” -> “EtherCAT” -> “Advanced Settings” -> “Mailbox” -> “AoE”
Fig.60: Assignment of AoE-NetID using the example of EL6224PortNo
The individual IO-Link ports for the master are allocated via the port number. The port numbers are allocated in ascending order from 0x1000. This means that IO-Link port 1 corresponds to PortNo 0x1000 and IO-Link Portn corresponds to PortNo 0x1000 + n-1.
The following specification applies to Beckhoff’s 4-port IO-Link masters:
- IO-Link port 1 corresponds to PortNo 0x1000
- IO-Link port 2 corresponds to PortNo 0x1001
- IO-Link port 3 corresponds to PortNo 0x1002
- IO-Link port 4 corresponds to PortNo 0x1003
ADS Indexgroup
As for CoE, the Indexgroup of an ADS command is specified as 0xF302 for the IO link data channel.
ADS Indexoffset
The IO link addressing with index and subindex is coded in the Indexoffset. The Indexoffset has a size of 4 bytes and is subdivided as follows: 2-byte index, 1-byte reserve, 1-byte subindex.
- Example: Indexoffset 0x12340056 corresponds to index 0x1234 and subindex 56