OpenWebNet
Encyclopedia
OpenWebNet is a Communication Protocol
Communications protocol
A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...

 developed by Bticino
Bticino
Bticino S.p.A. is an Italian metalworking company that operates in the field of electrical low voltage equipment used to residential, employment and production...

 since 2000.

OpenWebNet Protocol allow a “high level” interaction between a remote unit and Bus SCS
Bus SCS
SCS is an acronym for “Sistema Cablaggio Semplificato” . It uses a fieldbus network protocol and has applications in the field of home automation and building automation.-General Features:...

 of MyHome domotic system.

Latest protocol evolution has been improved to allow interaction with well known home automation systems like KNX
KNX (standard)
KNX is a standardized , OSI-based network communications protocol for intelligent buildings. KNX is the successor to, and convergence of, three previous standards: the European Home Systems Protocol , BatiBUS, and the European Installation Bus...

 and DMX512-A system, by using appropriate gateways
Gateways
Gateways may refer to:Books*Gateways , the seventh volume of the Repairman Jack books by F. Paul Wilson*Gateways , a 2001 crossover novel series*Strange Gateways, a collection of stories by E...

.

The OpenWebNet protocol is disclosed on MyOpen community.

OpenWebNet Protocol

The protocol is thought to being independent from the used technology.
For example it’s possible to use a supervisor software connected via Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

, via serial RS-232
RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...

 or via USB to a gateway that is directly connected to a domotic system.

Everyone can require protocol message extension. It's enough to propose your own RFC
Request for Comments
In computer network engineering, a Request for Comments is a memorandum published by the Internet Engineering Task Force describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems.Through the Internet Society, engineers and...

. It will be examined and disclosed if it respects OpenWebNet syntax.

Syntax

An OpenWebNet message is structured with variable length fields separated by the special character '*' and closed by '##'.

The characters admitted in the fields are numbers and the character “#”.

The structure of a message is therefore:
  • field1*field2*… *fieldN##


The following fields are admitted:
WHO
WHERE
WHAT
DIMENSION
VALUE

WHO

It characterizes the domotic system function to which the OpenWebNet message is referred.

For example: WHO = 1, characterizes the messages for lighting system management.

WHERE

It characterizes the set of objects to which the OpenWebNet message is referred. It can be a single object, a group of objects, a specific environment, the entire system, etc.

For every WHO (and therefore for every function) there is a specified WHERE table.

The tag WHERE can also contain optional parameters: WHERE#PAR1#PAR2… #PARn.

Example of where: all the lights of group 1, sensor 2 of zone 1 of alarm system, etc.

WHAT

It characterizes an action to do or a status to read. For every WHO (and therefore for every function) there is a specific WHAT table.

The field WHAT can also contain optional parameters: WHAT#PAR1#PAR2… #PARn.

Example of actions: switch ON light, dimmer to 75%, switch DOWN shutter, radio ON, etc.
Example of status: light ON, active alarm, battery unload, etc.

DIMENSION

Is a range of value that characterizes the dimension of the object to which the message is referred. For every WHO (and therefore for every function) there is a specific DIMENSION table.

It’s possible to require/to read/to write the value of one dimension.
Every dimension has a prefixed number of values, described in VALUE field.

Example of dimension: sensor temperature, loudspeaker volume, firmware version of a device, etc.

VALUE

It characterizes the read/written value of a written/required/read dimension.

Message

There are 4 types of OpenWebNet Message:

Command / Status Message

Status Request Message

Request/Read/Write Dimension Message

Acknowledge Message

Command / Status Message
*WHO*WHAT*WHERE##

Status Request Message
*#WHO*WHERE##

Request/Read/Write Dimension Message
Request:
*#WHO*WHERE*DIMENSION##
Read:
*#WHO*WHERE*DIMENSION*VALUE1*...*VALUEn##
Write:
*#WHO*WHERE*#DIMENSION*VALUE1*...*VALUEn##

Acknowledge Message
ACK:
*#*1##
NACK:
*#*0##

Gateway OpenWebNet

It's possible to interact with the SCS home automation
Home automation
Home automation is the residential extension of "building automation". It is automation of the home, housework or household activity. Home automation may include centralized control of lighting, HVAC , appliances, and other systems, to provide improved convenience, comfort, energy efficiency and...

 bus by using a specific gateway
Gateway (telecommunications)
In telecommunications, the term gateway has the following meaning:*In a communications network, a network node equipped for interfacing with another network that uses different protocols....

.

There are two typologies of gateways
Gateways
Gateways may refer to:Books*Gateways , the seventh volume of the Repairman Jack books by F. Paul Wilson*Gateways , a 2001 crossover novel series*Strange Gateways, a collection of stories by E...

 that allow a connection to the field bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

 by using different standard protocol
Communications protocol
A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...

s:
  • Gateway Ethernet
    Ethernet
    Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

     (Linux
    Linux
    Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

     based)
  • Gateway USB / RS232


Gateway Ethernet

The current implementation by BTicino is also an embedded
Embedded
- In science :* In mathematics, embedding is one instance of some mathematical object contained within another instance** Graph embedding* In computing, an embedded system is a special-purpose system in which the computer is completely encapsulated by the device it controls* In computing, embedding...

 web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....

. It works as a translator between OpenWebNet messages via TCP/IP and the SCS messages transmitted on the SCS bus.

Actually it is possible to control three different kinds of buses:
  • BUS SCS
  • KNX
    KNX (standard)
    KNX is a standardized , OSI-based network communications protocol for intelligent buildings. KNX is the successor to, and convergence of, three previous standards: the European Home Systems Protocol , BatiBUS, and the European Installation Bus...

  • DMX
    Digital Multiplex
    DMX512 is a standard for digital communication networks that are commonly used to control stage lighting and effects. It was originally intended as a standardized method for controlling light dimmers, which, prior to DMX512, had employed various incompatible proprietary protocols...



Gateway USB / RS232

The gateway is an interface that works as a translator between the OpenWebNet messages transmitted on USB or Serial and the SCS messages transmitted on the SCS bus.

Example

OpenWebNet message examples

Command Message

Switch Off of light 77
*1*0*77##

WHO = 1
WHAT = 0
WHERE = 77

Status Message

Scenario 1 of scenario unit 23 activated.
*0*1*23##

WHO = 0
WHAT = 1
WHERE = 23

Request status message

Status request of probe 1
*#4*1##

WHO = 4
WHERE = 1

Request Dimension Message

Request of Temperature Measured, probe 44
*#4*44*0##

WHO = 4
WHERE = 44
DIMENSION = 0

Read Dimension Message

Temperature Measured, probe 44
*#4*44*0*0251*2##

WHO = 4
WHERE = 44
DIMENSION = 0
VALUE1 = 0251 (T=+25,1°C)
VALUE2 = 2 (System in "cooling mode")

Write Dimension Message

Volume set at 50%, environment 2
*#16*#2*#1*16*##

WHO = 4
WHERE = #1
DIMENSION = 1
VALUE1 = 16

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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