check_scheme() :: :checksum | :crc

sequence_number() :: 0..3

t() :: %Jeff.Device{
  address: Jeff.osdp_address(),
  check_scheme: check_scheme(),
  commands: :queue.queue(term()),
  last_valid_reply: non_neg_integer(),
  secure_channel: term(),
  security?: boolean(),
  sequence: sequence_number()
}