Category: ZigBee

In ZigBee Cluster Library (ZCL) specifications, there are sometimes confusing points that developers do not quite understand, and I will try in this post to clarify a little bit about those level definitions in ZCL’s most-recent version, v7 (ZigBee document 07-5123 Revision 7).

  First of all, level is something generic. Keep that in mind. It can be light levels, which is often found in lighting systems, but it can also be anything, for example, water level, air pressure level, and etc.

However, as ZigBee is more widely adopted in home automation systems than other systems, where lighting is a key part, level cluster is more often used for connected lighting cases.  That is why starting ZCL v7,  the more general level cluster (cluster id 0x0008, chapter 3.10) derives a “level cluster for lighting” cluster, with the same cluster id 0x0008 (chapter 3.19).

    And I will clarify level definitions for lighting especially.

We will discuss ZigBee Green Power commissioning in this post, but first I will do a retrospective.

Retrospective

If you know ZigBee Green Power, or else you have read my previous post , you should have the idea of how a GPD (Green Power Device) differs from traditional ZigBee devices. Also, you should know that ZigBee devices need to act as GPP or GPS to work together with GPDs. Currently, we can implement GPP / GPS by Green Power Infrastructure Devices. Specifically proxy basic, combo basic and commissioning tool are three certifiable devices by to-date specification.

There are three important tables within GPP / GPS. They are: proxy table, sink table and translation table. Proxy table and sink table contribute to GPDF forwarding, while translation table contributes to GPDF execution.

GPDF forwarding

We have that one question left: how can we make these tables into the GPP / GPS ?

OK, let us talk a bit about ZigBee Green Power commissioning.

Green Power Commissioning Process

One should keep in mind: the commissioning process is designed for facilitating the ultra-low nature of GPDs.

Some GPDs are battery-less based on energy-harvesting technologies, so they can only transmit, and they cannot store network information.

There comes the uni-directional Green Power commissioning.

Some GPDs uses battery, so they can be more advanced in functions. For example, they can both transmit and receive, and they can keep network information.

There comes the bi-directional Green Power commissioning.

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ZigBee Meets ZigBee Green Power

ZigBee meets Green Power!

In ZigBee-3.0 specification suites,  ZigBee Alliance promotes the use of  ZigBee Green Power, however not people understands what it is.

However, ZigBee Green Power is in fact not new. Look back to 2012, ZigBee Green Power already emerges as an optional feature of ZigBee Pro. Perhaps due to lack of Green Power devices at that time, not many ZigBee stacks support the optional feature .

ZigBee Green Power is designed with ultra-low operations in mind. Thus it is possible to create ZigBee Green Power devices using batteries or even without batteries. This maintenance-free nature makes ZigBee Green Power attractive in certain application fields.

Inter-operability Problems

Making ZigBee Green Power an optional feature however creates inter-operability problems.

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