BACnet.Protocol.NetworkLayerProtocolMessage (bacstack v0.0.1)

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Network layer messages are used for prividing the basis for router auto-configuration, router maintenance and network layer congestion control.

The purpose of the BACnet network layer is to provide the means by which messages can be relayed from one BACnet network to another, regardless of the BACnet data link technology in use on that network. Whereas the data link layer provides the capability to address messages to a single device or broadcast them to all devices on the local network, the network layer allows messages to be directed to a single remote device, broadcast on a remote network, or broadcast globally to all devices on all networks.

See also ASHRAE 135 Clause 6.4.

Summary

Types

data()

Represents data for known BACnet network layer message types.

dnet()

Represents a network number.

msg_type_reserved()

The message type number range for reserved area messages.

msg_type_vendor()

The message type number range for vendor proprietary messages.

t()

Represents a message layer message (Network Service Data Unit - NSDU).

Functions

encode(message)

Encode the network layer protocol message into binary data.

Types

data()

@type data() ::
  (who_is_router_to_network :: dnet() | nil)
  | (i_am_router_to_network :: [dnet()])
  | (i_could_be_router_to_network :: {dnet(), perf_index :: byte()})
  | (reject_message_to_network ::
       {dnet(), reason :: byte(), reason_string :: String.t() | :undefined})
  | (router_busy_to_network :: [dnet()])
  | (router_available_to_network :: [dnet()])
  | (initialize_routing_table :: [
       {dnet(), port_id :: byte(), port_info :: binary()}
     ])
  | (initialize_routing_table_ack :: [
       {dnet(), port_id :: byte(), port_info :: binary()}
     ])
  | (establish_connection_to_network ::
       {dnet(), termination_time :: non_neg_integer()})
  | (disconnect_connection_to_network :: dnet())
  | (what_is_network_number :: nil)
  | (network_number_is :: {dnet(), :configured | :learned})

Represents data for known BACnet network layer message types.

dnet()

@type dnet() :: BACnet.Protocol.ApplicationTags.unsigned16()

Represents a network number.

msg_type_reserved()

@type msg_type_reserved() :: 0..107

The message type number range for reserved area messages.

msg_type_vendor()

@type msg_type_vendor() :: 0..127

The message type number range for vendor proprietary messages.

t()

@type t() :: %BACnet.Protocol.NetworkLayerProtocolMessage{
  data: data() | binary() | {vendor_id :: non_neg_integer(), binary()},
  msg_type: msg_type_vendor() | msg_type_reserved() | nil,
  network_message_type: BACnet.Protocol.Constants.network_layer_message_type()
}

Represents a message layer message (Network Service Data Unit - NSDU).

data is a binary if the type is in the reserved area (:reserved_area_start). data is a tuple for vendor proprietary messages, the actual data is a binary in the tuple.

Functions

encode(message)

@spec encode(t()) :: {:ok, binary()} | {:error, term()}

Encode the network layer protocol message into binary data.