Background

As mandatory element, each EtherCAT slave has a slave information interface (SII) which is accessible by the slave.

Physically, this is a special storage area for slave-specific data in an EEPROM memory chip. Its size is varaiable in the range of 1 kBits – 512 kBits (128 – 65536 Bytes).

For loadable firmware, the size of the SII is limited to 64 K. Because there is no separate EEPROM in the netX chips, the SII is virtually created in the netX.

After configuration, the firmware writes the content of the SII to the virtual EEPROM.

In case the application has created a custom object dictionary, the EtherCAT Slave does not have enough information to write the whole SII image.

In this case, the application has to write the SII data starting from address 0x80 using the SII related funtions at every startup of the device.

Please find more informations about the SII in the EtherCAT Slave Protocol API:

https://kb.hilscher.com/display/DL/EtherCAT+Slave

Create an SII image

With the help of the Conformance Test Tool (CTT) or TwinCAT, an SII image can be created from an ESI file.

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