ProtocolZD state machine
stateDiagram-v2 [*] --> Init: appProtocolZDStart Init --> Registering: connect push, send ident Registering --> Registered: response.register true Registering --> Registering: 30s timeout, retry Registered --> Registered: alive every 5 min Registered --> Registered: handle pull messages Registered --> Registered: push data when meter job completes