Chapter 5 - ZigBee, ZDO, and ZDP

Abstract

This chapter describes the ZigBee Device Object (ZDO) and the ZigBee Device Profile (ZDP). ZDO is simply the application running on endpoint 0 in every ZigBee device. This application, ZDO, keeps track of the state of the ZigBee device on and off the network, and provides an interface to the ZDP, a specialized application profile for discovering, configuring, and maintaining ZigBee devices and services on the network. ZDP contains a set of commands for discovering various aspects about nodes in the network. Each ZDP request in BeeStack requires a destination address, which may be unicast or broadcast, as the ZigBee specification allows. ZDP also contains a variety of standard services for querying the applications within those nodes. Binding provides a mechanism for attaching an endpoint on one node to one or more endpoints on another node. The ZDP Management services are really handy optional services used for reading the various tables contained within ZigBee nodes, and requesting certain common actions. ZDO is the local-state machine that controls the state of the ZigBee node on and off the network. When a node boots up, it does not necessarily join a network right away. It may go into low-power mode, and wait for a button-press, or some other event that causes the node to decide it needs to network. ZigBee provides no low-power API. ZigBee End-Devices are the only nodes in a ZigBee network that achieve long battery life.