ECAT servo

Free EtherCAT CiA402 servo drive implementation on STM32 (F1, F4), with Arduino example

EtherCAT is realtime Ethernet protocol for automation. It lets you control standard industrial equipment with your PC or laptop, without interface cards or special adapters. All it needs is just standard Ethernet card with RJ45 port. It offers low, very predictable latency, so it perfect motion control network for building modern CNC, robots and other machines. The most popular EtherCAT application protocol for servo drives seems to be CANopen (over EtherCAT) CiA402.

This project is free implementation of CoE CiA402 standard, for use with open motor controllers like ODrive, STMBL, or your next thing. Along the way, it shows how to do EtherCAT device development using free and open source tools.

CiA 402 implementation

Axis struct has states, transitions and action flags, its up for application to act on these.

cia402_axis_t cia402axis;                           // create instance of motion control axis
cia402_initialize(&cia402axis, &OD.Status_Word, &mockOD.ALstatus);  // initalize

// ...
while (true) {                                      // in main loop
    // ...                                          // read PDOs from CANbus,    
                                                    // or EtherCAT
    cia402_state_machine(&cia402axis, controlword); // process state machine

    if (axis.flags.axis_func_enabled) { /* implement your drive following command */ }
    if (axis->flags.hv_power_applied) { /* enable HV power if applicable */ }
    if (axis->flags.brake_applied) { /* release brake if applicable */ }

    if( /* application detected error condition */ ) {
        cia402axis.state = FAULT_REACTION_ACTIVE;    // trigger fault reaction
        cia402_state_machine(&cia402axis, controlword); // process SM
    }
}

Example applications

Example application for STM32 is is here

./examples dir contains platform.io projects showing how to use LAN9252 and AX58100 ESCs with STM32 and SOES library.

Documentation

Documentation in /docs contains progress log with rationale on some decisions

Hackaday

Hackaday.io project is here for more convinient discussion

Disclaimer

The EtherCAT Technology, the trade name and logo "EtherCAT" are the intellectual property of, and protected by Beckhoff Automation GmbH.