association_updated – gets sent if a pcp association group nodes have been changed
    event = "association_updated",
    node_id = 2,
    class_id = 58,
    channel_id = 0,
    group_id = 1,
    group_nodes = [ {node_id = 1, endpoint_id = 0} ]
fields type description
event string type of an event
node_id int a unique id of a ZWave device within a Zwave network
class_id int class_id + channel_id construct a unique id of a pcp for a ZWave device
channel_id int channel id
group_id int id of association group
group_nodes table array of endpoints in group(node_id and endpoint_id for each endpoint)