SCS is an acronym for "''Sistema Cablaggio Semplificato''" ("Simplified Cable Solution"). It uses a

fieldbus A fieldbus is a member of a family of industrial digital communication networks used for real-time distributed control. Fieldbus profiles are standardized by the International Electrotechnical Commission (IEC) as IEC 61784/61158. A complex autom ...

network protocol and has applications in the field of

home automation Home automation or domotics is building automation for a home. A home automation system will monitor and/or control home attributes such as lighting, climate, entertainment systems, and appliances. It may also include home security such ...

and

building automation Building automation (BAS), also known as building management system (BMS) or building energy management system (BEMS), is the automatic centralized control of a building's HVAC, HVAC (heating, ventilation and air conditioning), electrical, light ...

. It is used mainly in bTicino and Legrand installations.

General features

An SCS bus is based on a sheathed

twisted pair Twisted pair cabling is a type of communications cable in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced ...

formed of two flexible conductors; these are braided and unshielded with isolation 300/500V, SELV as double isolation is required – according to the rules adopted by CEI (International Electrotechnical Committee). The bus is unpolarized, devices are required to support the DC power supply in both polarity.

Wiring

Two kind of wiring are possible: *''Free cabling'' were a mix of bus and star topology are present, better for old houses *''Star wiring'' were all devices are connected to the switch rack, better for new houses

Communication

Across the SCS bus four different types of signals are transmitted in frequency modulation: * Electricity supply via 27 Vdc * Data with a frequency clock of 9600 Hz * Sound * Video The transmission protocol is the

CSMA/CA Carrier-sense multiple access with collision avoidance (CSMA/CA) in computer networking, is a link layer multiple access method in which carrier sensing is used. Under CSMA/CA, nodes attempt to avoid collisions by beginning transmission only af ...

Functions

Through the SCS bus you have the following functions: * Light control * Automation * Sound diffusion * Energy management * Thermoregulation * Video intercom * Alarm system All the listed functions share the same technology and the same procedures for configuration / installation.

Configuration

All devices connected to SCS bus must be manually configured, no autolearn is possible, apart Alarm system and extenders. Configuration assign an address and an operating mode. Two kind of configurations are possible: *''Physical'' - using numbered jumpers with different values

resistor A resistor is a passive two-terminal electronic component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active e ...

. Those are custom made devices and packages. SCSphysical configurators digits

*''Virtual'' - using a configuration

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

connected with an

ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

gateway. In this case the address and operating mode are written in a non volatile memory in every device. Applying a physical jumper override the virtual configuration wiping the memory.

Addressing details

Device addressing use three different 'digits' A, PL, GR. The A mean the room, the PL is the Point of Load in the room, and GR is the group. Group join loads in same or different rooms in a logical manner. Not all devices has group addressing. All devices must answer to room broadcast called AMB. All devices must answer to general broadcast called GEN. Physical and Virtual addressing has different limitations: Writing physical addresses use 2 digits. Writing virtual addresses use 4 digits. In big houses and buildings, SCS address extension is possible, were different address domains are connected via some bridges. Only some kind of messages can cross a bridge. Here the values of physical configuration jumpers: Note: It looks like the values of the configurators are measured, not from any official table. Resistor values are not between short difference. E.g. "4", it is in this table 471 kohm; if resistor is 1%, it is about 470 k ... 479 k. The original table from year 1999/2000 says: 0 = 4,7M, 1 = 825k, 2 = 681k, 3 = 562k, 4 = 475k, 5 = 392k, 6 = 332k, 7 = 274 k, 8 = 221k and 9 = 182k. All these values are found in the standard "E"-resistor value table (EIA E96) but not uniformly spaced (is that correct?). Resistor values in this list are official. However the table values above are useful because all the values fall inside the 1% resistor tolerance area specified by E96 (except value 3501/9 measured at 179k - a second example tested also gave a reading of 179k).

Certifications

Devices connected to the SCS bus ar
IMQ
certified and comply with these product standards (

International Electrotechnical Commission The International Electrotechnical Commission (IEC; ) is an international standards organization that prepares and publishes international standards for all electrical, electronics, electronic and related technologies. IEC standards cover a va ...

(IEC) EN 50428 - IEC EN 60669-1/A1 - IEC EN 60669-2-1 - IEC EN 50090-2-2 - IEC EN 50090-2-3 ).

Integration

You can interact with the SCS bus through a gateway and an open high-level protocol called OpenWebNet. Two kind of gateway exist: *Gateway

(

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

based) *Gateway

USB Universal Serial Bus (USB) is an industry standard, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

RS-232 In telecommunications, RS-232 or Recommended Standard 232 is a standard introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such as a compu ...

These gateways are bidirectional; they translate SCS frames into OpenWebNet frames, and the other way round. The open protocol OpenWebNet shared b
MyOpen

community A community is a social unit (a group of people) with a shared socially-significant characteristic, such as place, set of norms, culture, religion, values, customs, or identity. Communities may share a sense of place situated in a given g ...

, let everybody to build software that interact with SCS devices. SCS protocol is a proprietary bTicino protocol. Interaction with other field bus must happen only writing software that use OpenWebNet.