For programming EtherCAT applications, the most important prior step is to implement EtherCAT system interfaces, which defines relevant PDI (Process Data Image) consisting of a number of PDOs (Process Data Objects[^2]) for control signals. Etherlab is IgH’s open-source EtherCAT master stack software running on Linux, and provides a complete set of APIs on which users can configure real-time communication of a variety of EtherCAT slave devices with the master. There is no graphical tool for easy EtherCAT slave configuration.
Neuromeca's EtherCAT tool, which is based on EtherLab, is a GUI-based software that allows users to easily configure EtherCAT system interface. Using EtherCAT tool's automatic slave configuration function, PDO mapping can be easily performed by importing all connected EtherCAT slaves to the GUI environment. In addition, users can easily develop applications through automatic C++ code generation of EtherCAT tool and verify their applications using the online monitoring program provided by PlatformSDK.
This guide is intended to provide users with a concrete step-by-step guide to implement their own EtherCAT system interfaces and test them on STEP platforms. Since there are so many different variations of EtherCAT slaves, we consider two system configurations as examples and describe the method:
Tutorial 1 describes concrete step-by-step guide to configure system interface of Neuromeka Smart Actuators (CORE) with one Beckhoff I/O module.
Section 2 provides a quick guide to configure system interface of a Maxon motor and two Beckhoff I/O modules.
Users would not have serious difficulty in applying the same methodology to their system in hand.
EtherCAT Master STEP
The EtherCAT Master used in this demonstration is a STEP2, the hard real-time Linux EtherCAT master controller designed for automation systems, robotic devices, and applications requiring hard real-time control capability. Figure shows the STEP2 used in this demonstration. The STEP2 has two Ethernet ports with one for EtherCAT slave connection and the other for connecting to the host. It also provides eight GPIO ports and RS485 interface.
It is supposed that the Platform SDK has been set-up successfully. Every other software runtime and libraries, e.g. Linux and Xenomai, as well as other tools, e.g. etherlab, are already pre-installed in STEP platforms. If Platform SDK and EtherCAT Tool Software are not installed on developer's host PC, please find installer in Download Page. It is strongly recommended to follow the STEP manual for understanding the platform with the SDK.
Process data objects are (CANopen) data which should be exchanged during cyclic operation, e.g. actual position values, target torque, and the like. ↩