Example: Who Is

This example starts all necessary processes and scans the BACnet network for devices. Each device will then have their device object scanned. The result is printed to the output.

Code (taken from file examples/who_is.exs):

alias BACnet.Protocol.BACnetArray
alias BACnet.Protocol.BACnetDateTime
alias BACnet.Protocol.Services.IAm
alias BACnet.Protocol.ObjectTypes.Device
alias BACnet.Stack.Client
alias BACnet.Stack.ClientHelper
alias BACnet.Stack.Segmentator
alias BACnet.Stack.SegmentsStore
alias BACnet.Stack.Transport.IPv4Transport

# Set Log level to info to not get flooded by debug messages
# If you have discovery issues, you might want to put this after the process starts,
# to find out on which network interface we're listening
Logger.configure(level: :info)

# Start all necessary processes
# See the documentation if you need to start the transport layer on a specific network adapter

{:ok, _pid} = IPv4Transport.open(Client, name: IPv4Transport)
{:ok, _pid} = Segmentator.start_link(name: Segmentator)
{:ok, _pid} = SegmentsStore.start_link(name: SegmentsStore)

{:ok, _pid} =
  Client.start_link(
    name: Client,
    segmentator: Segmentator,
    segments_store: SegmentsStore,
    transport: IPv4Transport
  )

IO.puts("Sending broadcast WhoIs service request to BACnet network...")

# Send broadcast Who-Is service request and wait 10 seconds for all responses
{:ok, iam_responses} = ClientHelper.who_is(Client, 10_000)

IO.puts("#{length(iam_responses)} device(s) responded, scanning now all found devices...")

# Now iterate over the responses and read the BACnet Device object to display some data
for {{dest_ip, dest_port}, %IAm{} = iam} <- iam_responses do
  case ClientHelper.read_object(Client, {dest_ip, dest_port}, iam.device,
         allow_unknown_properties: true
       ) do
    {:ok, %Device{} = device} ->
      objects_count = BACnetArray.size(device.object_list)

      IO.puts(
        "Found device #{device.object_name} (ID #{iam.device.instance}) on IP address #{:inet.ntoa(dest_ip)}:#{dest_port}:\n" <>
          "\t using BACnet protocol revision #{device.protocol_revision}, \n" <>
          "\t with segmentation supported #{device.segmentation_supported} (max. #{device.max_segments_accepted} segments), \n" <>
          "\t application uses firmware version #{device.firmware_revision}, \n" <>
          "\t it offers #{objects_count} object(s), \n" <>
          "\t the device is approximately running since " <>
          NaiveDateTime.to_iso8601(
            BACnetDateTime.to_naive_datetime!(device.time_of_device_restart.datetime)
          ) <> "\n"
      )

    {:error, err} ->
      IO.puts(
        "Found device with ID #{iam.device.instance} on IP address #{:inet.ntoa(dest_ip)}:#{dest_port}, " <>
          "however reading the device object failed for reason " <> inspect(err)
      )
  end
end

This example can be run:

• if installed as dependency: mix run deps/bacstack/examples/who_is.exs
• if working on bacstack: mix run examples/who_is.exs