occupied - parking occupancy status ("occupied" or "free");parking_session_iterator - short serial number of parking session. Iterator (number) is incrementing when new parking session starts (0-7);
previous_status_duration_min - duration of previous sensor status;
message_trace_id - system message-id;parking_session_iterator - short number of parking session. Iterator is incrementing when parking session starts (0-7);
occupied - parking occupancy status ("occupied" or "free");
heartbeat_message_counter - the value increases for every following heartbeat during single occupancy state (0-11);