@type discovered_slave() :: %{
  position: non_neg_integer(),
  station: non_neg_integer(),
  identity: map() | nil,
  al_state: atom() | nil,
  al_status_raw: non_neg_integer() | nil,
  al_error?: boolean() | nil,
  al_status_code: non_neg_integer() | nil,
  topology: %{dl_status: binary() | nil, active_ports: [0 | 1 | 2 | 3]}
}

@type t() :: %EtherCAT.Scan.Result{
  al_states: %{optional(non_neg_integer()) => map()},
  backend: EtherCAT.Backend.t(),
  discovered_slaves: [discovered_slave()],
  observed_faults: [map()],
  topology: %{slave_count: non_neg_integer(), stations: [non_neg_integer()]}
}