ZigBee applications - Part 6: Profiles

[Part 1 reviews ZigBee data transmission along with an example that demonstrates how to initiate various data request mechanisms. Part 2 discusses ZigBee's lack of a standard C API and looks at an API sampling from the four "Golden Unit" ZigBee vendors. Part 3 describes PAN IDs, extended PAN IDs, and channels, as well as application examples. Part 4 examines ZigBee node types, the network address, MAC addresses, groups and broadcasts. Part 5 covers concepts relating to ZigBee's application-level compatibility, including endpoints, clusters, commands and attributes.]

4.6 Profiles
Every data request in ZigBee is sent (and received) on an Application Profile. Application Profile IDs are 16-bit numbers and range from 0x0000 to 0x7fff for public profiles and 0xbf00 to 0xffff for manufacturer-specific profiles.

Think of a profile as a domain space of related applications and devices. Public profiles are those specified by the ZigBee Alliance (as opposed to private profiles specified by individual OEMs).

Home Automation is a public application profile which defines a wide range of ZigBee networked devices intended for use in the home, including lights and switches, wall outlets, remotes, thermostats, air-conditioners, and heaters. Another public profile, Commercial Building Automation, defines ZigBee devices such as advanced lights and switches, and keyless entry and security systems.

Any number of Application Profiles, both public and manufacturer-specific, may exist in a single ZigBee network. In fact, any number of profiles may exist in a single node on the network, separated on different endpoints.

The ZigBee Alliance continues to work on public profiles to ensure they match the needs of OEMs producing products. It is the OEMs in the ZigBee Alliance who define the profile in the first place. Table 4.10 shows a short list of the ZigBee public profiles.

Public profiles are designed so that products from one manufacturer (X) can work, right out-of-the-box, with products from another manufacturer (Y). For example, a thermostat from Honeywell can work with a variable-airflow-valve from Trane, or a light from Philips can work with a switch from Leviton.

ZigBee members may also apply for what is called a private profile. Private profiles, officially called Manufacturer Specific Profiles (or MSPs), are not defined by the ZigBee Alliance, but instead are defined by the OEMs making the products. Private profiles are used for those applications that do not need to interact with other vendors' products.

4.6.1 Public Profiles
All of the devices pictured in Figure 4.22 are part of the Home Automation profile. Once commissioned, all these devices perform their appropriate actions, simply and effectively.

The light switches (both on/off and dimmer) just work as light switches should, and the temperature is sent dutifully to the thermostat once each minute, which controls the heating and/or cooling unit. Lights may be dimmable or not, and may be three-way (toggle) or two-way (on/off).

The Freescale solution supports the Home Automation public profile out-of-the-box, including a large sample of ready-made HA devices such as lights, thermostats, and temp sensors. All the devices can be monitored by the PC through the ZigBee Environment Demo (ZeD). I'll not describe the ZigBee Environment Demo more here, since the Freescale documentation already does an adequate job.

Nearly all public profiles use the ZigBee Cluster Library, so I'll leave the example and details to Chapter 6, "The ZigBee Cluster Library."