ieee1888-green energy Standards in the Internet of Things (iii)

Four. Realization of 1888 protocol in realityShortly after the adoption of the 1888 standard, the University of Tokyo in Japan submitted its own implementation (see http://133.11.168.39/dist/), the author does not understand the Japanese, do not understand the above meaning, but the general view of the University of Tokyo's related applications have been continuing, and do a good job, The version has been rising and the application scenario is expanding. The text is not very understanding, the program can look, the following is the number 201310 of the 1888 schematic package (probably the October 2013 version) features:
The code is well-structured, although the note is a little bit, but the naming standard is strictly adhered to, so take a moment, read carefully, it is not difficult. The code can only run under Linux, not a "pity". The code is written in C language. Code is not dependent on any third-party libraries, including parsing XML and parsing HTTP is done by itself, so the release and deployment of code is very simple. The combination of the above two features allows the code to be used anywhere under Linux, and is very versatile.

Regarding the realization of the University of Tokyo, this article does not discuss, the Japanese-speaking colleagues can help interpret the translation.

On the Chinese side, the world is connected by a IEEE1888 development platform (http://open.ieee1888.org/home.html), which has a standard introduction and the corresponding SDK, interested colleagues can download their own research.
Both of these implementations are based on Web service (SOAP), and in the implementation process, due to some features of the Web service, the <transport> outer layer of the standard specification is also wrapped in a similar <dataRQ>,< Nodes such as Datars>, the naming of such nodes is nonstandard, so this extension is debatable.
In fact, in the standard, there is no requirement that the 1888 Protocol's bearer protocol requires soap. The SOAP implementation is strict but the compatibility is poor (the biggest problem is probably the above mentioned node and the namespace), so I suggest instead of using the Http+xml method directly, not the http+soap+xml way, and generally do not adopt the namespace. This benefit is simple, easy to implement and easy to interconnect.
In the development of future standards, it is advisable to further stipulate the details of the agreement, such as naming.

Five. Application of 1888 protocol in acquisition system

Under the 1888 Standard Architecture, the main workflow of a collection system (using the Trap method) and the key points of implementation are as follows:

1. In the configuration of the gateway, you must have access to the registration service.

2. The gateway uses the registration service to register itself and the measured points it manages using the registration method.

3. Registration service after the registration of a gateway, according to the registration situation, to the gateway to subscribe to the data of the relevant points (data method, trap protocol, the purpose of the appropriate storage address).

4. When the gateway receives storage's subscription request, the data of the measured points involved is sent to the storage (data method) on time.

5. If the network is abnormal, the network Guan whether to cache the data, the standard is not specified.

6. If the storage changes, how the gateway side checks and can migrate to the new storage, the standard is not specified.

7. How to cancel the Gateway data subscription, the standard is not specified.

8. The query method of the gateway can accept external commands that query the values of the measured points (that is, set the value of the action and generate the associated action).

9. The data method of the gateway can accept external commands that can set the value of the measured points (that is, set the values of the actions and generate related actions).

10. Using a uniform rule to create a roll call, the URI format (not mandatory) is recommended in IEEE1888.

11. When registering, the unit, data type of the measuring point, whether writable (can be set) must be specified (this part is non-standard, must be expanded)

12. The 1888 standard, the definition of the group is not very detailed, if support point group, need to do some expansion. For example, nesting groups are not allowed.

Six. Some thoughts on the 1888 standard

From the above introduction of the 1888 standard, it can be seen that the standard is mainly used in slow, "autonomous" networks, such as building energy saving, utilities, smart furniture and other real-time requirements of the occasion, "autonomy" means the entry of equipment, exit are free, no managers, minimize dependence and mandatory. Thus, the 1888 standard only pay attention to the transmission of data, and did not pay attention to how to ensure the transmission of such data and other measures, details of the provisions also need to be strengthened.

In short, the 1888 standard is a relatively generalization of the standard, 1888.1,1888.2,1888.3,1888.4 and other sub-standard is the "strengthening" measures. These sub-standards are described below.