wireless technologies like ZigBee offer many benefits, but they also present unique challenges when it comes to installation and commissioning. In a wired network, you can follow the wires to determine which switch has control lights. When there are no wires, it is necessary a different method and set of tools to get to the network to operate the way you want. A standards-based protocol
as ZigBee offers clear and significant benefits - interoperable building blocks, a wider range of options for application developers, and no danger of obsolescence due to the use of methods and proprietary solutions.
In addition to a standards-based protocol, the ZigBee Alliance has and continues to provide the controls and standards-based methodology for commissioning ZigBee systems. These will ensure that the instruments and devices can interoperate using the same over-the-air programming commands.
Under ZigBee, there are three major classes of parameters that can be ordered:
- membership, which includes all aspects of how networks and devices to determine which devices are included (or excluded) from a specific network
- groups and associations, which includes all aspects of how devices on the same network logically connected to each other or belong to groups in which logical one-to-many or -a many-many connections are needed.
- Application, in which specific settings are set (as the thermostat levels or programs when the lights come on).
These parameters classes can also be commissioned in sequence. Adhesion occurs first, to ensure that devices together and form the correct network. Groups and associations to guarantee that the devices can connect to the right devices within this network. And finally, the application settings have a duty to ensure correct application behavior.
all the commands necessary to achieve belonging and Groups and Associations commissioning can be found in ZigBee Commissioning Cluster and ZigBee device profile.
ZigBee Commissioning Cluster
The ZigBee Alliance has specified a cluster startup, which provides a standard set of ZigBee over-the-air commands for membership commissioning.
The key control is used to reach the mass membership is the command request Restart device. This command, which can be sent either by a commissioning tool or through another device (such as the coordinator, or a gateway for remote commissioning), indicates a device to start again with a specific startup attributes set.
It 'important to note that a complete set of these attributes (called a boot attribute set or SAS) will determine how a device starts up and choose to be part of a network to join. The SAS can be placed in a device at the place of installation, but by definition, a SAS already exists (pre-programmed) in the device before it arrives.
The SAS includes the following attributes:
- The launcher control, explained below
- The extended PAN ID (or EPID) network (a global network unique identifier)
- the channel mask, which determines which channels the device should search for a network to join
- security information, such as the network key and address of the trust center
the start command is used to determine how the device should join the network:
- as a coordinator, and then start the network with the values of the supplied attributes
- Take any network
- to return to the network with an accurate EPID
- suppose that is already a part of a network with the specific setting values (also known as the start mode connected)
for example, a device with the following values SAS has the most flexibility in being able to join any network (but correspondingly , has the highest risk of entering the wrong network):
- join any
- With a channel mask that allows you to enter the "all channels"
- No network security key
security is an important part of ZigBee, as it provides the means to prevent unwanted monitoring of the system by encrypting all packet communications protocols, 128-bit high-security AES.
An important requirement to provide, for example a secure system is the mass in function of security keys. In addition to ensuring that the devices have the right keys to encrypt and decrypt the exchange of packets, security can also be used to exclude the devices to a network (as a part of the commissioning States).
ZigBee Device Profile
The ZigBee Device Profile (ZDP) provides a set of standard commands can provide (or assist ) in commissioning in the following ways:
- ZDP binding and Managers of the group to offer all the necessary commands to provide commissioning and binding group.
- More Commands for ZDP management can be useful in helping to Mass. For example, the ZDP commands and network discovery service can be used to examine your network and take decisions put into service devices. The ZDP Node Manager can be used to control "Registration Permit" and the theme "Dare" commands to manage in a more direct membership.
Conclusions
In a perfect world, the devices would have commissioned themselves. You could simply turn on, turn them on, and then stand back and watch what network devices work should unite, as security has been working in the network, the device (or devices) that should bind, and which devices should communicate with.
Up to that perfect world comes, it is the commissioning functions can leverage based on standards set by the ZigBee Alliance to help and make the job a lot easier.
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