# Type Alias SubscriptionOptions

SubscriptionOptions: (
| { minPeriod?: undefined; period?: number; policy?: "fixed" }
| { minPeriod?: number; period?: undefined; policy?: "instant" }
) & { format?: "delta"; path?: Path }

A path object with optional criteria to control output

#### Type declaration

- { minPeriod?: undefined; period?: number; policy?: "fixed" }

  - ##### `Optional` minPeriod?: undefined

    If policy=immediate or ideal, consecutive messages will be buffered until minPeriod has expired so the receiver is not swamped.

  - ##### `Optional` period?: number

    The subscription will be sent every period millisecs.

  - ##### `Optional` policy?: "fixed"

    - `fixed` - Send the last known values every `period`.
    - `inline` - Send all changes as fast as they are received, but no faster than `minPeriod`. With this policy the client has an immediate copy of the current state of the server.
- { minPeriod?: number; period?: undefined; policy?: "instant" }

- ##### `Optional` format?: "delta"

  The signal K format to use for the message. Only `delta` is currently supported. See Signal K Data Model

- ##### `Optional` path?: Path

  The path to subscribe to.

- Defined in subscriptionmanager.ts:67