EtherCAT

• Pure-Elixir EtherCAT master
• Nerves-first, runs on standard Linux too
• Good fit: discrete I/O, Beckhoff terminal stacks, 1 ms to 10 ms cyclic loops, diagnostics tooling
• Not the right fit: sub-millisecond hard real-time control

Try It in Livebook

kino_ethercat provides interactive Livebook cells for bus discovery, I/O control, and diagnostics — the fastest way to explore a live ring.

Installation

def deps do
  [{:ethercat, "~> 0.1.0"}]
end

You need CAP_NET_RAW or root for raw socket access:

sudo setcap cap_net_raw+ep _build/dev/lib/ethercat/priv/raw_socket

Quick Start

# Discover the ring
EtherCAT.start(interface: "eth0")
EtherCAT.await_running()
EtherCAT.slaves()
#=> [%{name: :slave_0, station: 0x1000, pid: #PID<...>}, ...]
EtherCAT.stop()

# Exchange cyclic PDOs
defmodule MyApp.EL1809 do
  @behaviour EtherCAT.Slave.Driver

  def process_data_model(_), do: [ch1: 0x1A00]
  def encode_signal(_, _, _), do: <<>>
  def decode_signal(_, _, <<_::7, bit::1>>), do: bit
  def decode_signal(_, _, _), do: 0
end

EtherCAT.start(
  interface: "eth0",
  domains: [%EtherCAT.Domain.Config{id: :io, cycle_time_us: 1_000}],
  slaves: [
    %EtherCAT.Slave.Config{name: :coupler},
    %EtherCAT.Slave.Config{name: :inputs, driver: MyApp.EL1809, process_data: {:all, :io}}
  ]
)

EtherCAT.await_operational()
EtherCAT.subscribe(:inputs, :ch1)   # receive {:ethercat, :signal, :inputs, :ch1, value}
{:ok, bit} = EtherCAT.read_input(:inputs, :ch1)

Full API and guides: hexdocs.pm/ethercat