Descriptors

An application may need to obtain information about the nodes of the network in which it runs, as described in Section 3.4.6. For this, it uses information stored in descriptors in the nodes.

There are three mandatory descriptors and two optional descriptors stored in a node. The mandatory descriptors are the Node, Node Power and Simple descriptors, while the optional descriptors are called the Complex and User descriptors

For each node, there is only one Node and Node Power descriptor, but there is a Simple descriptor for each endpoint. There may also be Complex and User descriptors in the device.

The Node, Node Power and Simple descriptors are outlined below. For full details of the descriptors, refer to Section 9.2.1.

Simple descriptor

The Simple descriptor for an application includes:

  • The endpoint on which the application runs and communicates

  • The ZigBee device type that the application implements

  • The ZigBee clusters that the device type implements

  • Whether there are corresponding Complex and User descriptors

  • Lists of input and output clusters (see Section 3.4.1) that the application uses and provides, respectively

Parent topic:Descriptors

Node descriptor

The Node descriptor contains information on the capabilities of the node, including:

  • Type (End Device, Router or Coordinator)

  • Frequency band in use (868 MHz, 902 MHz or 2400 MHz)

  • IEEE 802.15.4 MAC capabilities - that is, whether:

    • the device can be a PAN Coordinator

    • the node implements a Full-Function or Reduced-Function IEEE 802.15.4 device

    • the device is mains powered

    • the device is capable of using MAC security

    • the receiver stays on during idle periods

  • Manufacturer code

  • Stack compliance revision (of the ZigBee PRO Core specification to which the stack complies - prior to Revision 22/ZigBee2017, these bits were reserved and set to zero)

  • Maximum buffer size (the largest data packet that can be sent by an application in one operation)

Parent topic:Descriptors

Node power descriptor

The Node Power descriptor contains information on how the node is powered:

  • Power mode - whether the device receiver is on all the time, or wakes up periodically as determined by the network, or only when an application requires it (for example, during button press).

  • Available power sources - indicates whether the mains supply, or rechargeable or disposable batteries (or any combination) can be used to power the device.

  • Current power sources - indicates which power source (mains supply, or rechargeable or disposable batteries) is currently being used to power the device.

  • Current power source level - indicates the level of charge of the current power source.

Parent topic:Descriptors

Parent topic:Application level concepts