Glossary · Industrial communication
EtherCAT Slave Information (ESI)
Also known as: ESI file, ESI, EtherCAT SubDevice Information
German: ESI-Datei
In EtherCAT, the EtherCAT Slave Information (ESI) is the XML device description, specified by the EtherCAT Technology Group, that tells configuration tools a subdevice's identity, supported mailbox protocols, process data objects, object dictionary, sync manager settings and distributed clock modes.
- Industrial communication
- Standards
- Technical documentation
In one sentence
The ESI file is the XML description of an EtherCAT subdevice: identity, process data, mailbox protocols, object dictionary and clock modes.
Example
An integrator copies the ESI files of a new labeler's servo drives into the EtherCAT configurator, which then recognizes the drives when it scans the line and suggests their process data mapping.
How it applies
- Engineering: The configurator matches devices found on the network with ESI files by vendor ID, product code and revision number. A missing or mismatched revision is a common reason why a device isn't recognized.
- Commissioning: The ESI file sets defaults for the process data mapping and the Distributed clock mode; the configuration tool writes the resulting network configuration for the main device. Parts of the ESI data are also stored in the device's EEPROM (the SII).
- Versioning: New device revisions come with updated ESI files. Keep the ESI version that matches the installed hardware revision with the project.
- Documentation: The documentation team names the ESI file for each device revision, where to get it, the default and alternative process data mappings and the supported clock modes. The ESI describes the device to the tool; it doesn't replace the manual.
ESI vs. ENI
The ESI describes one device type. The EtherCAT Network Information (ENI) file is generated by the configurator and describes one concrete network for the main device.