The „ecmasterlib“ offer an easy way to use EtherCAT with EEROS or in a standalone project.

• EtherCAT stack: The EtherCAT stack from Acontis, see The Acontis EtherCAT Stack.
• ecmasterlib: This library provides an easy interface to the EtherCAT stack. The library initializes the stack and takes over the periodic sending and receiving of the data on the bus. It provides the following basic interfaces
  • Elmo.hpp: An interface for Elmo drives
  • Beckhoff/EL1008.hpp: An interface for digital input terminal
  • Beckhoff/EL2008.hpp: An interface for digital output terminal
  • Beckhoff/EL3004.hpp: An interface for analog input terminal
  • Beckhoff/EL4004.hpp: An interface for analog output terminal

You may need to implement your own interfaces for other drives and terminals.

Once the EtherCAT stack has been installed and the demo application is running, the ecmasterlib can be installed.

$ cd path/to/working/directory
$ git clone https://gitlab.ost.ch/tech/inf/public/ecmasterlib
$ cd ecmasterlib
$ mkdir externalLib
$ cp ''<classB_path>''/SDK/LIB/Linux/x64/libAtemRasSrv.a externalLib
$ cp ''<classB_path>''/SDK/LIB/Linux/x64/libEcMaster.a externalLib
$ mkdir build-x86-64
$ cd build-x86-64
$ cmake -DCMAKE_INSTALL_PREFIX=/absolute/path/to/working/directory/install-x86-64 ..
$ make
$ make install

The examples show how to use the interfaces, e.g.

ecmasterlib::device::beckhoff::EL1008 inputs{};
auto &stack = ecmasterlib::EcMasterlibMain::createInstance(argc, argv, inputs);
 
std::cout << inputs[0] << std::endl; // reads first digital input channel

You create an interface instance which must be passed to the EtherCAT stack. See the examples within ecmasterlib. Elmo drives could be used as follows

ecmasterlib::device::Elmo drive{};
auto &stack = ecmasterlib::EcMasterlibMain::createInstance(argc, argv, drive);
sleep(10);
std::cout << "init start\n";
drive.init([&stack]() { stack.sync(); });
drive.setMode(ecmasterlib::device::Elmo::Mode::PROFILE_VELOCITY);
drive.setTargetVelocity(1000);
drive.setMaximumTorque(300);
 
std::cout << "loop start\n";
while(stack.isRunning()) {
  std::cout << "Current Position: " << drive.getPosition() << '\n';
  sleep(1);
}

The components EtherCATInterfaceElmo_config, getDrivesBlock and setDrivesBlock need to be adjusted whenever you change the variables, which are transmitted via PDOs (periodic sent/received messages by the EtherCAT bus). These components must also be adapted when creating a new EEROS application.

1. Study produced ENI file carefully (use XML viewer). Under <config><processimage><inputs> and <outputs> you find bitsize and offset of all transmitted values.
2. Adjust headerfile accordingly, negative offset values indicate that the entry is not going to be used.
3. Make necessary adaptions in getDrivesBlock and setDrivesBlock.

interface is specific for Gold Twitter drives from ElmoMC. Other drives (i.e. Maxon Maxpos 50/5) need a different interface. You may copy and adapt EtherCATInterfaceElmo for your drive type.

EEROS > EtherCATInterfaceElmo > ecmasterlib & EtherCATInterfaceBase > Acontis Stack

Detailed description