# `EtherCAT.Domain.Config`
[🔗](https://github.com/sid2baker/ethercat/blob/main/lib/ethercat/domain/config.ex#L1)

Declarative configuration struct for a Domain.

Fields:
  - `:id` (required) — atom identifying the domain; also used as the ETS table name
  - `:cycle_time_us` (required) — cycle time in microseconds; must be a whole-millisecond value (`>= 1_000`, divisible by `1_000`)
  - `:miss_threshold` — consecutive miss count before domain halts, default `1000`
  - `:recovery_threshold` — consecutive unhealthy cycles before the domain
    tells the master that runtime recovery is required, default `3`

The high-level master API owns logical address allocation. If you use
`EtherCAT.start/1`, domains are declared by intent (`id`, cycle time, miss
threshold) and the master assigns non-overlapping logical windows before
slaves program their FMMUs.

If you bypass the master and start a domain directly through the low-level
runtime API, that path still accepts an explicit `:logical_base` option.

# `t`

```elixir
@type t() :: %EtherCAT.Domain.Config{
  cycle_time_us: pos_integer(),
  id: atom(),
  miss_threshold: pos_integer(),
  recovery_threshold: pos_integer()
}
```

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*Consult [api-reference.md](api-reference.md) for complete listing*