Commit b2f490ce authored by ankraft's avatar ankraft
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Added a new directory to work on version 4.0 of SDT.

Changed the license to 3-clause BSD.
Changed various version numbers from 3.0 to 4.0.
parent d7bd559b
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Repository for the Smart Device Template (SDT).
**Version 3.0**
**Version 4.0**
Note that this project runs under Apache 2.0 license. Read the [LICENSE](LICENSE) in this repository, or refer to [](
Note that this project runs under the 3-Clause BSD License. Read the [LICENSE](LICENSE) in this repository, or refer to [](
Any contributions made to this project must comply with the aforementioned license.
......@@ -12,23 +12,23 @@ Any contributions made to this project must comply with the aforementioned licen
The Smart Device Template (SDT) is a template which is used to model the capabilities, actions and events of connected devices. The intent of the SDT is to be able to model any type of connected device using a well accepted and standardised format. The main application of SDT is to enable a uniformly structured Application Programmer’s Interface (API) to applications that need to interact with connected devices. Usually, these applications would communicate to devices using an Abstraction Layer as an intermediary logic. The Abstraction Layer „hides“ the technology-specific, native language format of devices of different technology type from the applications.
[Read the full Introduction.](SDT/schema3.0/docs/
[Read the full Introduction.](SDT/schema4.0/docs/
## Quick Links
- ['domain.xsd' Version 3.0](SDT/schema3.0/src/domain.xsd)
- [UML Diagram of the SDT 3.0](SDT/schema3.0/docs/ ([source](SDT/schema3.0/docs/SDT_UML.uxf))
- ['domain.xsd' Version 4.0](SDT/schema4.0/src/domain.xsd)
- [UML Diagram of the SDT 4.0](SDT/schema4.0/docs/ ([source](SDT/schema4.0/docs/SDT_UML.uxf))
## Content
You can find further Information here:
- [Introduction to the SDT](SDT/schema3.0/docs/
- [SDT Components](SDT/schema3.0/docs/
- [SDT Build System](SDT/schema3.0/docs/
- [Examples](SDT/schema3.0/docs/
- [Links & References](SDT/schema3.0/docs/
- [Changelog](SDT/schema3.0/docs/
- [Introduction to the SDT](SDT/schema4.0/docs/
- [SDT Components](SDT/schema4.0/docs/
- [SDT Build System](SDT/schema4.0/docs/
- [Examples](SDT/schema4.0/docs/
- [Links & References](SDT/schema4.0/docs/
- [Changelog](SDT/schema4.0/docs/
<?xml version="1.0" encoding="UTF-8" ?>
<!-- - HGI Device Abstraction Layer - - - - - - - - - - - - - - - - - - - - -->
<!-- -->
<!-- Extends the standard build with targets for: -->
<!-- - generate XML schema the from Relax NG (xml) description -->
<!-- - validate DAL documents against the XML Schema -->
<!-- - generate HTML documentation from DAL documents -->
<project name="importing" basedir="." default="schemas">
<import file="etc/common.xml"/>
<!-- Read the namespace declarations from a file (to get linebreaks) - - - -->
<loadfile property="schema.xmlns" srcFile="${basedir}/etc/schema.xmlns"/>
<!-- The RNG file the XML and RNC schemas are generaed from - - - - - - - -->
<property name="" value="domain"/>
<property name="schema.rng" value="${path.src}/${}.rng"/>
<!-- HTML - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
<!-- -->
<!-- Generate HTML documentation from domain definitions in the test -->
<!-- directory. The module classes included via the extends tagged are -->
<!-- included in the documentation - so an xinclude capable XSL engine is -->
<!-- needed. -->
<!-- This needs Ant version 1.8+ and it must be augmented with an current -->
<!-- version of Xerces. Download the binray distribution and place the put -->
<!-- xml-apis.jar and xercesImpl.jar in the Ant lib directory. -->
<target name="html">
<mkdir dir="${path.genbase}" />
<xslt basedir="${basedir}/test" destdir="${basedir}/gen/html"
<param name="destdir" expression="${basedir}/gen/html"/>
<!-- Schemas - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
<!-- -->
<!-- The schema is specified using Relax NG (xml) and trang is used to -->
<!-- generate the XML schema. The schema is also generated in Relay NG -->
<!-- compact syntax, which is used by some validating editors (e.g. emacs) -->
<!-- The resulting schemas need some additional patching before thy are -->
<!-- usable -->
<target name="schemas">
<java jar="${basedir}/lib/trang.jar" fork="true">
<arg value="${schema.rng}"/>
<arg value="${basedir}/etc/${}.rnc"/>
<!-- So that the editor does not complain about include directives, the -->
<!-- resulting schema is included in another schema, which includes the -->
<!-- necessary element definitions. To be able to do this the -->
<!-- definition for Imports must be deleted from this generated schema. -->
<replace file="${basedir}/etc/${}.rnc"
token="Imports = element Imports { Domain* }?" value=""/>
<java jar="${basedir}/lib/trang.jar" fork="true">
<arg value="${schema.rng}"/>
<arg value="${path.src}/${}.xsd"/>
<!-- Can't validate against the generated schema unless we add the -->
<!-- target and default namespaces ... -->
<replace file='${path.src}/domain.xsd'
<!-- In addition the xml:base tag, which is added automatically when -->
<!-- including a document, must also be permitted by out schema. -->
<!-- The schema generated from RNG is almost correct schema ... but -->
<!-- the schemaLocation is wrong. -->
<replace file='${path.src}/domain.xsd'
token="xml.xsd" value=""/>
<!-- Validate - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
<!-- -->
<!-- Check the Device Description conforms to the Device Abstraction -->
<!-- Schema. Note that we need to activate support for XML includes -->
<target name="validate" depends="">
<schemavalidate warn="true">
<fileset dir="${basedir}/test" includes="*.xml"/>
<attribute name="" value="true"/>
<schema namespace=""
file="${path.src}/domain.xsd" />
<schema namespace=""
file="${basedir}/etc/XInclude.xsd" />
<schema namespace=""
file="${basedir}/etc/XMLSchema.xsd" />
# Changelog
## Changes in 4.0
## Changes in 3.0
- Renamed ``<RootDevice>``to ``<Device>`` and ``<Device>`` to ``<SubDevice>``,
- Added complex data types: *Struct* and *Arrays*.
- Simplified the UML diagram. Split the UML diagram into two parts, one for the base elements and one for the data types.
- In the UML diagram: Moved ``<extends>`` into the UML ``<ModuleClass>`` element (easier to read).
- Added support to specify *Units of Measurement* to data types,
- Added ``<Doc>`` to ``<Domain>`` and other elements.
- ``<Doc>`` is now always the first part of an element.
- Changed ``<DeviceInfo>`` element to a list of ``<Characteristic>``.
- Added ``<Characteristic>`` list to ``<Modules>`` and ``<ModuleClasses>``.
- The ``<data>`` element in ``<Event>`` is now optional to support events without attached or associated data.
- In Actions: Added ``<Args>`` as a surrounding list around a list of ``<Arg>``.
- Added *Constraints* to ``<DataType>``.
- Added optional *name* attribute to ``<DataType>``. This mandatory for elements of a *struct*.
- Restructured the [RNG](SDT/schema3.0/src/domain.rng) file for better readability and maintainability.
- In the [RNG](SDT/schema3.0/src/domain.rng)/[XSD](SDT/schema3.0/src/domain.xsd): Changed cardinality of the occurrence of elements that are part of a list of elements (e.g. ``<SubDevices><SubDevice>…</SubDevice></SubDevices>`` from „zero or more“ to „one or more“ when the surrounding list element itself is optional (to avoid empty lists).
## Changes in 2.0.1
- Added missing "uri" data type.
## Changes in 2.0
- Introduced RootDevice to support hierarchical embedded devices.
- Added new data types (byte, float, array, enum, date, time, datetime, blob, uri)
- Added ``readable`` and ``eventable`` to data points.
- Added optional ``<SerialNumber>``, ``<VendorURL>`` and ``<FirmwareVersion>`` elements to DeviceInfo
- Added optional ``<Doc>`` element to Event
- Changed the optionality of the ``<DataPoint>``'s ``type`` attribute to "required".
- Added [UML diagram](SDT/schema2.0/docs/
- Changed the namespace for the XSD from "" to "".
\ No newline at end of file
# Examples and Contributions
[A simple example](#simpleExample)
[Multi Socket Electrical-Extension-Block](#mseeb)
<a name="simpleExample"></a>
## A very simple SDT example
In the ideal case, a large organization or SDO would define a widely-applicable set of [ModuleClasses](, each of which could be used as needed to compose the description of a complex device. In order to show the appoach, this section will create a few example ModuleClasses based on - or inspired by - featues in the Echonet Lite protocol. Please note that the examples shown in this document are very "cut down" and by no means represent a true representation of Echonet Lite.
The Echonet Consortium has standardized their specifications within IEC/ISO (IEC62394, ISO/IEC24767-1, ISO/IEC24767-2, IEC62480, ISO/IEC14543-4-1, ISO/IEC14543-4-2, IEC62457) and they provide a comprehensive collection of various types of home appliances relevant to SmartGrid applications as ECHONET Device objects (see []( ).
For the example in this document, to show re-use of ModuleClass definitions, two complex devices are chosen which have some common features and hence could be expected to both use some of the same ModuleClasses: an air conditioner and a washing machine.
<tr><th>Funtionality</th><th>Air Conditioner</th><th>Washing Machine</th></tr>
<tr><td>operationStatus</td><td>operates on/off</td><td>operates on/off</td></tr>
<tr><td>measuredCumulativePowerConsumption</td><td>the cumulative power consumption</td><td>the cumulative power consumption</td></tr>
<tr><td>installationLocation</td><td>this sets/reads a string text describing the location (room) of the air-conditioner.</td><td>this sets/reads a string text describing the location (room) of the washing machine.</td></tr>
<tr><td>setTimer</td><td>(not applicable. there is no preset start for an air-conditioner)</td><td>This sets/reads use the on/off timer</td></tr>
Based on the simplified example above, the two appliances will need the ModuleClasses below:
- *air-conditioner*: operationStatus, measuredCumulativePowerConsumption, installationLocation;
- *washing-machine*: operationStatus, measuredCumulativePowerConsumption, and setTimer.
<ModuleClass name="operationStatus">
<DataPoint name="operationStatus" writable="true">
<Doc>This property sets/reads the ON/OFF status.</Doc>
<SimpleType type="boolean"/>
<Event name="operationStatus">
<ModuleClass name="measuredCumulativePowerConsumption">
<DataPoint name="measuredCumulativePowerConsumption" writable="false">
<Doc>This indicates cumulative power consumption of the device in increments of 0.001kWh.</Doc>
<SimpleType type="integer"/>
<ModuleClass name="installationLocation">
<DataPoint name="installationLocation" writable="true">
<Doc>This property indicates the installation location</Doc>
<SimpleType type="string"/>
<Event name="installationLocation"> </Event>
<ModuleClass name="onTimerSetting">
<DataPoint name="onTimer" writable="true">
<Doc>Timer value (HH:MM)</Doc>
<SimpleType type="time"/>
The structure and the according SDT now looks like this:
<tr><td colspan="2" width="50%"><b>Example1.SDT</b></td></tr>
<tr><td> </td><td>Namespace information</td></tr>
<tr><td> </td><td>Modules (contains ModuleClasses)</td></tr>
<tr><td> </td><td>operationStatus<ul>
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- Example1 SDT inspired by some Echonet Lite examples -->
<Domain xmlns=""
<!-- Various examples for module classes -->
<ModuleClass name="operationStatus">
<DataPoint name="operationStatus" writable="true">
<Doc>This property sets the ON/OFF status.</Doc>
<SimpleType type="boolean"/>
<Event name="operationStatus">
<ModuleClass name="installationLocation">
<DataPoint name="installationLocation" writable="true">
<Doc>This property indicates the installation location</Doc>
<SimpleType type="string"/>
<Event name="installationLocation"> </Event>
<ModuleClass name="measuredCumulativePowerConsumption">
<DataPoint name="measuredCumulativePowerConsumption" writable="false">
<Doc>This indicates cumulative power consumption of the device in increments of 0.001kWh.</Doc>
<SimpleType type="integer"/>
<ModuleClass name="onTimerSetting">
<DataPoint name="onTimer" writable="true">
<Doc>Timer value (HH:MM)</Doc>
<SimpleType type="time"/>
<a name="mseeb"></a>
### Multi Socket Electrical-Extension-Block
This example is a specification for an imaginged device, a connected extension block with multiple power socket where each of the sockets are modeled as a
separate *SubDevice*.
# Frequently Asked Questions
## What is the HGI?
## What is the SDT?
# Introduction to the SDT
The SDT (Smart Device Template) is an initiative from HGI to find consensus amongst various SDOs and industry alliances to derive a common approach for device modelling. HGI and partners have the approach to agree on a set of automation commands, following a common syntax, which are sufficient to model most home appliance functions.
At the time of writing, every software developed for home gateways or internet-of-things gateways needs to be capable of using various different protocols (ZigBee, UPnP, EchonetLite, DECT ULE, etc) to interact with a range of devices designed for the home environment. This adds extreme overheads in integrating, checking and updating code. The purpose of SDT is to describe devices and device services in a way which is independent of the LAN technology, in a format which is convenient and reliable for integration in modern code (Java, C/C++, ...).
The key goals of the SDT are: (1) keep it simple, especially for manufacturers to contribute device information; (2) modularity for functions and device types; (3) make it easy for developers to create unified APIs; (4) be independent of underlying home-area network technologies; (4) enable extendibility of the system in place without service interruption; (5) allow a pass-through mechanism to enable use of proprietary or technology-specific functions.
In general a description of device (or complex appliance) behaviour can be made in many ways, with various kinds of constraints:
1. no constraints (e.g. using OWL 2.0 or even more "flexibly" RDF)
2. moderate constraints (e.g. using XML and a related extensible XSD template)
3. strict constraints (typical for a device certified to interoperate with a specific LAN protocol)
HGI chose to use the approach "moderate constraints" (XSD based) because for software development it offers ease of use and a good compromise. In particular, if there are few or no constraints on control parameters then few automatic checks can be made to detect if the software parameters are appropriate for each device integrated. XML and XSD languages were chosen because they are familiar to many developers, can be parsed with common software tools, and can still be created and interpreted by humans if necessary.
HGI believes that Device information models based on XML and extensible XSD need some guidelines. If every possible feature of every existing LAN technology and appliance were allowed to be described in any formally correct way, then the results would be a modern Babel, no better than today's system of widely different and wildly competing automation protocols.
Therefore HGI proposes to recommend a certain structure (template) for the information model(s), but to allow extensions. Naturally, the more industry consensus is achieved for a single recommended template, the greater the utility for software developers (and users).
The SDT approach is to define re-usable basic functions (or services), labelled "ModuleClass" in the figure below, which can represent the typical functions found in many home automation systems, such as "on/off", "dim a lamp", "receive events from binary sensor", "read data from sensor", etc. Each ModuleClass is composed of a (small) number of actions, datapoint read/write operations, or asynchronous events. For example, an "on/off" ModuleClass would consist perhaps of just one Action, but a "ReadKeypad" Action might have a number of possible events, each with some data value and (usually) a sequence-ID or timestamp start/stop to indicate when and how long each key was pressed.
![SmartHome Device Template (XSD) for a generic device (simplification)](images/SDT_simplified.png)
**SmartHome Device Template (XSD) for a generic device (simplification)**
The SDT represents the device models introduced in the above figure by using an XSD schema to allow formal checking of compliance for XML device descriptions of specific appliances. The modularity goal in the XSD schema is achieved with re-usable XSD fragments ("ModuleClass" in the figure).
Complex devices or appliances can then be described by an appropriate set or collection of the agreed XSD fragments (ModuleClasses), as indicated in the figure, which also shows an optional DeviceInfo XSD fragment to allow noting of static information such as device manufacturer name, device firmware version, etc etc.
HGI has discussed with many SDOs to validate these concepts. SDT is designed to take into account the list of "services" compiled by the SAREF project (
The SDT supports the use of a set of templates for generic devices or appliances (e.g. for a dimmable lamp, a basic washing machine, etc, which would be specific instances of the "Device" object , which form the basis of APIs used by application developers. These templates can also be referenced by manufacturers creating XML documents to describe their specific products. For example, the SDT enables specification of a generic washing machine template, with on/off, set-wash-temperature, pause and a few other commands, which could be referenced by a manufacturer as the schema for a XML description of a basic model washing machine. The SDT allows for vendor-specific additional commands (ModuleClasses) to suit specific product types.
The interoperability benefits can potentially partially be obtained even without a fully complete interoperability of the SDT. For example, the most common functions can be modeled with SDT, and more particular functions can be modeled with technology-specific, proprietary, or seldom-used aspects.
Various details about the recommended structure for SDTs are described in the next sections. The key point to keep in mind is that HGI sought a compromise between, at the one extreme, complete flexibility (which could describe any device, of any complexity) and, at the other extreme, a rigid structure which could be 100% validated and lead to validated software APIs.
## Definitions
This section provides an overview about the SDT 4.0 definitions and element hierarchy. Terms to be described in detail in this section are:
| Term | Definition |
|Domain | Unique name, or "wrapper" which acts like a namespace, set by the organization creating the SDT, allowing reference to a package of definitions for the contained ModuleClasses and device definitions. Can be referenced when extending ModuleClasses. It has two possible uses: to select the scope of a technology domain, or to set the scope of a use case domain (like Home, SmartGrid, etc) |
| Device | Physical, addressable, identifiable appliance/sensor/actuator. |
| Sub-Device | A device (usually one of several) which may be embedded in a Device and/or is addressed via another Device. |
| ModuleClass | Specification of a single service with one or more service methods, the involved abstracted data model and related events. The expectation is that each separate service which may be used in many kinds of Devices (like PowerON/OFF, Open/Close, ...) will be described by a ModuleClass which can be re-used in many Device definitions. |
| Module | Instantiation of a ModuleClass for a specific Device or SubDevice|
**Definitions of SDT Elements.**
A major decision, facilitating validation of code and signalling, was to describe services (functionality) of devices in terms of ModuleClasses made up of combinations of three kinds of elements:
1. DataPoints which are aspects of the Device that can be read/written,
2. Actions which consist of more complex sequences of operations;
3. Events which can be signalled ("published") by devices asynchronously.
This ModuleClass structure is shown in the figure below and is a major part of the SDT which is illustrated in detail in the following figure:
![UML description of device functionality in terms of Actions, DataPoints and Events](images/MC.Action.DataPoint.Event.png)
**UML description of device functionality in terms of Actions, DataPoints and Events**
## How should SDT work?
The basic concept is that a manufacturer, organisation or global SDO would define its preferred Smart Device Template, in XML, specified by and based on an XSD. Using that XSD, manufacturers or indeed hobbyists could "describe" existing or new devices by means of XML files, specifying the capabilities and the parameters needed to control the devices.
Assuming that the XML files conform to the specified XSD and to some guidelines described in this document, software developers could readily create APIs able to "parse" the XML-descriptions of devices and (assuming the underlying LAN technology of the device is supported by the software/hardware environment in the gateway) operate the equipment.
The key to making software reliably interoperate with various technologies is to define in the SDT a finite and convenient to use number of functions (which is the decision of the SDO which are commonly used and can therefore be reliably re-used in software for one type of device or another.
For the convenience of users and developers, it would also be possible to collect the device descriptions of common "modules" (types of) appliances so that the operations of "a generic air-conditioner" could be agreed and re-used often, adapting descriptions of special models with just some special features added as local extensions. Agreeing on the definition of "a generic XYZ appliance" is rather time-consuming, so such "repository" may not become standardised, however the basic approach has huge benefits even if such an archive (also known as a "hierarchical ontology") is never formally agreed.