ᐅ Smart Home Building Control Systems / Home Automation / Bus Systems
Created on: 1 Sep 2016 13:15
M
Mycraft
This thread aims to shed some light on the topic...
Because it is becoming increasingly relevant, and the average builder is usually overwhelmed by the many offers, costs, possibilities, pitfalls, and problems involved in construction—especially when it comes to the topic of:
Modern electrical systems in the home during sales discussions. Since I live myself in a house with KNX electrical installation, I will also use examples to take a closer look at the KNX system.
Unfortunately, the term Smart Home is not protected. This results in any house with motion detectors or switchable wireless outlets from discount stores being defined as a Smart Home. It often happens that either only the bare minimum equipment is installed, or the salesperson is so enthusiastic about a certain system that, in the heat of the moment, people install devices that are completely outdated.
However, nothing here is smart... these remain "dumb" add-on components that simply increase comfort temporarily. Why temporarily? Because people are lazy, and eventually it becomes annoying to look for the remote control for the outlets, as it is always in a different place, and because motion detectors cannot be adjusted 100% to the needs of the occupants.
Every builder should become as familiar with their electrical system as with the choice of tiles or other elements of their future home. Too often, people rely on the general contractor (GC) to take care of everything.
If John Doe buys a motor vehicle today, he compares models for days, looks at features, and adds this and that to the wish list. No one wants a car without central locking or electric windows. Still, 20 years ago, it was perfectly normal—and these cars sold like hotcakes. It’s similar with home electrical systems today... you build a house, all options are open, and you could buy extras. But you opt out. Often due to lack of money, but also due to ignorance and entrenched ways of thinking, like “The switch does what it’s supposed to, it turns the light on and off.” What many don’t realize is that much more is possible. People may have heard somewhere that there is something out there, but they are absolutely unsure what, how, and why?
However, over the next 20 years, home electrical systems will likely develop as cars, phones, or televisions have. Nowadays, most people do not want cars without comfort features like central locking, nor phones with cords or CRT TVs.
A modern home electrical system typically looks like this:
The systems are interconnected via wireless or wired networks. They communicate using protocols and operate in the background without needing manual intervention. That means: the blinds automatically lower in strong sunlight to protect the house from excessive solar heat, or the skylight closes when it starts to rain.
Today we have access to a wide range of building automation technology that is available to everyone, unlike just a few decades ago.
We have simple systems with little or no intelligence, such as:
- Conventional electrical installations with push dimmers, impulse relays, etc.
Here, additional comfort is minimal, expandability is practically zero, and almost everything must be operated manually.
Mid-range systems, where many proprietary home automation solutions are found, include:
- Loxone
- Somfy Tahoma
- innogy Smart Home
- HomeMatic
- Philips Hue
- Apple HomeKit
- free@Home
Due to their limited functionality and generally less complex technology—especially regarding installation and programming—these systems tend to be cheaper than comparable building automation systems. The scope of functions and device packages should be carefully reviewed. Proprietary home automation systems are less flexible in terms of features and future expandability compared to building automation systems.
Then, there is the premium class of building automation technology (bus systems):
- LCN
- LON
- WAGO I/O
- Z-Wave
- KNX / EIB
These systems fulfill almost every wish and offer possibilities that many builders only dream of. However, they require thorough planning and are among the most expensive at first glance.
Compared to conventional installations and adding comfort functions in a conventional way, bus systems are becoming increasingly attractive and cost-effective.
Here is a graphic from a major German manufacturer with a presence in all sectors.
The idea behind building automation technology is:
- Integration of as many systems and components as possible (lighting, outlets, heating, ventilation, garden, television, sound system, etc.)
- Monitoring and control of systems from central points
- Expandability and flexibility
- Increase in comfort and ease of use
KNX offers the greatest integration of all systems because it is an open standard. This means the protocol is openly accessible, and all manufacturers who produce and sell KNX products must ensure their products comply with the KNX specifications. In other words, you can use existing experience, but the product must be designed so that it can be operated by any other KNX device from one or several manufacturers. This contrasts with proprietary systems (LOXONE, free@Home, Somfy, etc.), where you are tied to one manufacturer and thus become dependent on them. If production stops and devices in the house break down, you end up with expensive scrap and may have to start from scratch.
KNX is different. There are over 400 manufacturers and millions of products that all “speak” to each other. If a module fails, it is simply removed and replaced by another. It doesn’t matter which manufacturer the new module comes from, as long as it bears the KNX logo. KNX costs money, unfortunately. But as described earlier, the price decreases with the number of functions you want in the house. The debate about whether you need it or not is pointless here. The technology is available, and you have the choice. You can use it or not. As the saying goes: “You can get around by horse carriage too.”
An example:
If you have, for example, 15 roller shutters in the house and want them to be controllable not only locally at the window (without wireless), but also at central points (e.g., at the front door or in the bedroom), and if you want control on each floor, then the initial investment price becomes more reasonable. Because the additional components required for a conventional roller shutter installation (extra switches, separable relays, junction boxes) to provide this functionality are not free, and the labor to wire the shutters accordingly must also be paid for.
Because it is becoming increasingly relevant, and the average builder is usually overwhelmed by the many offers, costs, possibilities, pitfalls, and problems involved in construction—especially when it comes to the topic of:
Modern electrical systems in the home during sales discussions. Since I live myself in a house with KNX electrical installation, I will also use examples to take a closer look at the KNX system.
Unfortunately, the term Smart Home is not protected. This results in any house with motion detectors or switchable wireless outlets from discount stores being defined as a Smart Home. It often happens that either only the bare minimum equipment is installed, or the salesperson is so enthusiastic about a certain system that, in the heat of the moment, people install devices that are completely outdated.
However, nothing here is smart... these remain "dumb" add-on components that simply increase comfort temporarily. Why temporarily? Because people are lazy, and eventually it becomes annoying to look for the remote control for the outlets, as it is always in a different place, and because motion detectors cannot be adjusted 100% to the needs of the occupants.
Every builder should become as familiar with their electrical system as with the choice of tiles or other elements of their future home. Too often, people rely on the general contractor (GC) to take care of everything.
If John Doe buys a motor vehicle today, he compares models for days, looks at features, and adds this and that to the wish list. No one wants a car without central locking or electric windows. Still, 20 years ago, it was perfectly normal—and these cars sold like hotcakes. It’s similar with home electrical systems today... you build a house, all options are open, and you could buy extras. But you opt out. Often due to lack of money, but also due to ignorance and entrenched ways of thinking, like “The switch does what it’s supposed to, it turns the light on and off.” What many don’t realize is that much more is possible. People may have heard somewhere that there is something out there, but they are absolutely unsure what, how, and why?
However, over the next 20 years, home electrical systems will likely develop as cars, phones, or televisions have. Nowadays, most people do not want cars without comfort features like central locking, nor phones with cords or CRT TVs.
A modern home electrical system typically looks like this:
The systems are interconnected via wireless or wired networks. They communicate using protocols and operate in the background without needing manual intervention. That means: the blinds automatically lower in strong sunlight to protect the house from excessive solar heat, or the skylight closes when it starts to rain.
Today we have access to a wide range of building automation technology that is available to everyone, unlike just a few decades ago.
We have simple systems with little or no intelligence, such as:
- Conventional electrical installations with push dimmers, impulse relays, etc.
Here, additional comfort is minimal, expandability is practically zero, and almost everything must be operated manually.
Mid-range systems, where many proprietary home automation solutions are found, include:
- Loxone
- Somfy Tahoma
- innogy Smart Home
- HomeMatic
- Philips Hue
- Apple HomeKit
- free@Home
Due to their limited functionality and generally less complex technology—especially regarding installation and programming—these systems tend to be cheaper than comparable building automation systems. The scope of functions and device packages should be carefully reviewed. Proprietary home automation systems are less flexible in terms of features and future expandability compared to building automation systems.
Then, there is the premium class of building automation technology (bus systems):
- LCN
- LON
- WAGO I/O
- Z-Wave
- KNX / EIB
These systems fulfill almost every wish and offer possibilities that many builders only dream of. However, they require thorough planning and are among the most expensive at first glance.
Compared to conventional installations and adding comfort functions in a conventional way, bus systems are becoming increasingly attractive and cost-effective.
Here is a graphic from a major German manufacturer with a presence in all sectors.
The idea behind building automation technology is:
- Integration of as many systems and components as possible (lighting, outlets, heating, ventilation, garden, television, sound system, etc.)
- Monitoring and control of systems from central points
- Expandability and flexibility
- Increase in comfort and ease of use
KNX offers the greatest integration of all systems because it is an open standard. This means the protocol is openly accessible, and all manufacturers who produce and sell KNX products must ensure their products comply with the KNX specifications. In other words, you can use existing experience, but the product must be designed so that it can be operated by any other KNX device from one or several manufacturers. This contrasts with proprietary systems (LOXONE, free@Home, Somfy, etc.), where you are tied to one manufacturer and thus become dependent on them. If production stops and devices in the house break down, you end up with expensive scrap and may have to start from scratch.
KNX is different. There are over 400 manufacturers and millions of products that all “speak” to each other. If a module fails, it is simply removed and replaced by another. It doesn’t matter which manufacturer the new module comes from, as long as it bears the KNX logo. KNX costs money, unfortunately. But as described earlier, the price decreases with the number of functions you want in the house. The debate about whether you need it or not is pointless here. The technology is available, and you have the choice. You can use it or not. As the saying goes: “You can get around by horse carriage too.”
An example:
If you have, for example, 15 roller shutters in the house and want them to be controllable not only locally at the window (without wireless), but also at central points (e.g., at the front door or in the bedroom), and if you want control on each floor, then the initial investment price becomes more reasonable. Because the additional components required for a conventional roller shutter installation (extra switches, separable relays, junction boxes) to provide this functionality are not free, and the labor to wire the shutters accordingly must also be paid for.
Motion Detectors:
Comparison between Motion Detectors and Presence Detectors:
While presence detectors need to respond to the slightest movements, motion detectors are primarily used to monitor large corridors, outdoor areas, or similar spaces. The main function of motion detectors is to switch on the light when clear movements are detected, with this function programmable based on brightness levels. Additionally, the light remains on as long as a movement is detected and only turns off once the area is completely still. Although the basic principle is similar with presence detectors, their design features a fine tuning that allows the light to be switched off when no longer needed. The highly sensitive sensor reacts to subtle changes in light and, thanks to a high-resolution detection field, can intelligently control the lighting by switching it on and off as required. This type of detector essentially “thinks along,” making everyday life easier. You no longer need to worry about operating the light switch. In fact, light switches can be omitted entirely in passage areas such as corridors, halls, dressing rooms, and staircases.
The internal structure of both types is shown here. The difference is clearly visible. Presence detectors have multiple PIR sensors, while motion detectors usually have only one.
Presence Detector:
Motion Detector:
Comparison between Motion Detectors and Presence Detectors:
While presence detectors need to respond to the slightest movements, motion detectors are primarily used to monitor large corridors, outdoor areas, or similar spaces. The main function of motion detectors is to switch on the light when clear movements are detected, with this function programmable based on brightness levels. Additionally, the light remains on as long as a movement is detected and only turns off once the area is completely still. Although the basic principle is similar with presence detectors, their design features a fine tuning that allows the light to be switched off when no longer needed. The highly sensitive sensor reacts to subtle changes in light and, thanks to a high-resolution detection field, can intelligently control the lighting by switching it on and off as required. This type of detector essentially “thinks along,” making everyday life easier. You no longer need to worry about operating the light switch. In fact, light switches can be omitted entirely in passage areas such as corridors, halls, dressing rooms, and staircases.
The internal structure of both types is shown here. The difference is clearly visible. Presence detectors have multiple PIR sensors, while motion detectors usually have only one.
Presence Detector:
Motion Detector:
Binary Inputs:
Binary inputs are simple devices that detect binary events—that is, a 1 or a 0 (also On/Off)—and send this information to the bus, allowing status messages to be output or other functions to be triggered.
A counting function, for example for water consumption, can easily be implemented using a binary input if you have a water meter with a pulse output or reed contact.
Binary inputs are usually available as DIN rail mount devices with 4/6/8/16/32 channels, or as flush-mount versions (also called pushbutton interfaces) with 2/4/6 channels. Of course, other channel variations exist, but these are the most common. Another distinction is that binary inputs are available for 230V alternating current and for 0-30V direct current, as well as potential-free options.
Anything that can open or close a contact can be connected to the binary inputs, which then transmits this information to the bus and, according to the programming, can be displayed on switches, displays, or other output devices.
Besides the previously mentioned water meter, you can also send status information from window/door contacts, leak detectors, smoke detectors, cistern fill levels, or even a standard on/off light switch to the bus this way.
Binary inputs are simple devices that detect binary events—that is, a 1 or a 0 (also On/Off)—and send this information to the bus, allowing status messages to be output or other functions to be triggered.
A counting function, for example for water consumption, can easily be implemented using a binary input if you have a water meter with a pulse output or reed contact.
Binary inputs are usually available as DIN rail mount devices with 4/6/8/16/32 channels, or as flush-mount versions (also called pushbutton interfaces) with 2/4/6 channels. Of course, other channel variations exist, but these are the most common. Another distinction is that binary inputs are available for 230V alternating current and for 0-30V direct current, as well as potential-free options.
Anything that can open or close a contact can be connected to the binary inputs, which then transmits this information to the bus and, according to the programming, can be displayed on switches, displays, or other output devices.
Besides the previously mentioned water meter, you can also send status information from window/door contacts, leak detectors, smoke detectors, cistern fill levels, or even a standard on/off light switch to the bus this way.
Temperature Sensors:
Standalone temperature sensors with direct KNX connection for indoor or outdoor use are rare and practically never available for less than 50 euros (per unit). With other bus systems, this is significantly cheaper, which is why other systems like 1-Wire are sometimes used for temperature measurement within KNX setups when needed.
Temperature sensors are also integrated in room temperature controllers, occupancy detectors, tactile sensors, or other bus devices if equipped accordingly, allowing their use for temperature measurement.
The advantage of direct KNX-capable temperature sensors is that they can be calibrated directly and often come with many additional features from the manufacturer. These are not just simple "dumb" temperature probes but independent devices with evaluation units, statistical functions, logical operations, and more.
There are also REG and UP devices that allow the connection of multiple temperature sensors, making the cost per measurement point more economical overall.
Here are a few examples:
Standalone temperature sensors with direct KNX connection for indoor or outdoor use are rare and practically never available for less than 50 euros (per unit). With other bus systems, this is significantly cheaper, which is why other systems like 1-Wire are sometimes used for temperature measurement within KNX setups when needed.
Temperature sensors are also integrated in room temperature controllers, occupancy detectors, tactile sensors, or other bus devices if equipped accordingly, allowing their use for temperature measurement.
The advantage of direct KNX-capable temperature sensors is that they can be calibrated directly and often come with many additional features from the manufacturer. These are not just simple "dumb" temperature probes but independent devices with evaluation units, statistical functions, logical operations, and more.
There are also REG and UP devices that allow the connection of multiple temperature sensors, making the cost per measurement point more economical overall.
Here are a few examples:
In addition, there are suitable sensors for every task within the building automation systems.
These include: humidity sensors (often combined with temperature), mixed gas/air quality sensors (often combined with CO2), leak detectors, light meters (lux sensors), anemometers, pH sensors, global radiation sensors, current and voltage sensors, rain and soil moisture sensors, water level detectors, vehicle detection sensors, laser distance meters, and various types of optical sensors for different purposes.
Sensors are often combined, which eliminates the need for additional processing units and allows multiple environmental factors to be measured and transmitted simultaneously. This naturally lowers the cost for the end user and increases the system’s appeal.
All of this expands the overall functionality of the system and provides “eyes and ears” that enable the house or apartment to autonomously make decisions in response to occurring events. Predefined parameters can be executed in a fixed or flexible manner, for example, using hysteresis or self-learning algorithms. This can adjust the performance of the ventilation system while cooking or stop irrigation in the garden during rain or prevent it from starting if rain is expected.
Here are a few examples.
Temperature/Humidity/Climate
Sensor / Controller for Water Quality
[B][B][B]Global Radiation Sensor[/B][/B][/B]
Air Humidity, Temperature, Soil Moisture
These include: humidity sensors (often combined with temperature), mixed gas/air quality sensors (often combined with CO2), leak detectors, light meters (lux sensors), anemometers, pH sensors, global radiation sensors, current and voltage sensors, rain and soil moisture sensors, water level detectors, vehicle detection sensors, laser distance meters, and various types of optical sensors for different purposes.
Sensors are often combined, which eliminates the need for additional processing units and allows multiple environmental factors to be measured and transmitted simultaneously. This naturally lowers the cost for the end user and increases the system’s appeal.
All of this expands the overall functionality of the system and provides “eyes and ears” that enable the house or apartment to autonomously make decisions in response to occurring events. Predefined parameters can be executed in a fixed or flexible manner, for example, using hysteresis or self-learning algorithms. This can adjust the performance of the ventilation system while cooking or stop irrigation in the garden during rain or prevent it from starting if rain is expected.
Here are a few examples.
Temperature/Humidity/Climate
Sensor / Controller for Water Quality
[B][B][B]Global Radiation Sensor[/B][/B][/B]
Air Humidity, Temperature, Soil Moisture
Gateways in an Automated/"Smart" Home:
A gateway can be seen as both a gateway and a key. It connects different computer networks and technologies to ensure ongoing communication and interoperability. This includes linking various protocols as well as creating synergies between devices—for example, converting emails into faxes or SMS into emails. To make a house "smart," "intelligent," or whatever term you prefer, gateways are essential. Manufacturers of end products do not make it easy, as each one usually favors its own system for various reasons.
A smart home is well known as a residence where technical components are interconnected, can be controlled both centrally and decentrally, and at the same time develop synergies—for example, when the lighting automatically turns on upon opening the door, or when leaving the house triggers the away mode and activates the alarm system. Controlling lighting with a smartphone (e.g., using Philips Hue or Osram Lightify) or electrically lowering blinds (e.g., with Somfy TaHoma) does not automatically make it a smart home, but rather a modern technical setup. To truly qualify as intelligent and smart living, these systems must develop synergies and respond to each other—this is possible in part through gateways.
The more diverse components a smart home contains, each using proprietary communication methods, the greater the number of gateways needed to ensure communication. Since there is no universal standard for all devices worldwide, we rely on one or more common standards for communication protocols (TCP/IP, KNX, Z-Wave, ZigBee, Bluetooth, Wi-Fi, Modbus, etc.). This allows various components on both hardware and software levels to be connected and controlled, configured, and monitored from a single application, such as a web browser.
Gateways come in many forms and variants, either as hardware or as software modules.
Some systems take the inconvenient approach of trying to combine as many gateways as possible into a single "universal gateway" device. This often results in the end user paying for unnecessary features and/or devices functioning unstably and prone to failures. Having a dedicated gateway for each protocol is much more elegant and allows the full functionality of each communication channel to be utilized without restrictions, as bandwidth and other parameters are tailored specifically.
Here is a list of protocols and manufacturers that can be connected today. Devices from different manufacturers can then communicate, for example, using the KNX medium. (Of course, many more options exist, but covering them all would go beyond this scope.)
Z-Wave, ZigBee, EnOcean, Bluetooth, Homematic, Wi-Fi, DALI, CAN, LON, M-BUS, RS232, RS485, TCP/IP, IoT (Alexa, Sonos, etc.), HTTP, MQTT, SNMP, DMX, MODBUS, BOSCH 4A, 1-Wire, effeff BCM925, EsserNet, Honeywell MB100.10, Warema, Somfy, Hue, Hörmann, Velux, Daikin, Becker, ekey, AMX, Crestron, Panasonic, Axis, Berbel, Miele, etc.
In addition, various software concepts can perform similar functions on platforms like a Raspberry Pi, such as IPSymcon, SmarthomeNG, Openhab, FHEM, ioBroker, HomeKit, and others. These software solutions take the path of total control and sit on top of the system, monitoring, managing communication, and enhancing it with logic functions. The downside is that if the server fails, the entire system usually goes offline and becomes operable only manually. In decentralized systems, a complete failure almost never occurs (except during a power outage, which can also be mitigated), making the risk of total failure much lower.
A gateway can be seen as both a gateway and a key. It connects different computer networks and technologies to ensure ongoing communication and interoperability. This includes linking various protocols as well as creating synergies between devices—for example, converting emails into faxes or SMS into emails. To make a house "smart," "intelligent," or whatever term you prefer, gateways are essential. Manufacturers of end products do not make it easy, as each one usually favors its own system for various reasons.
A smart home is well known as a residence where technical components are interconnected, can be controlled both centrally and decentrally, and at the same time develop synergies—for example, when the lighting automatically turns on upon opening the door, or when leaving the house triggers the away mode and activates the alarm system. Controlling lighting with a smartphone (e.g., using Philips Hue or Osram Lightify) or electrically lowering blinds (e.g., with Somfy TaHoma) does not automatically make it a smart home, but rather a modern technical setup. To truly qualify as intelligent and smart living, these systems must develop synergies and respond to each other—this is possible in part through gateways.
The more diverse components a smart home contains, each using proprietary communication methods, the greater the number of gateways needed to ensure communication. Since there is no universal standard for all devices worldwide, we rely on one or more common standards for communication protocols (TCP/IP, KNX, Z-Wave, ZigBee, Bluetooth, Wi-Fi, Modbus, etc.). This allows various components on both hardware and software levels to be connected and controlled, configured, and monitored from a single application, such as a web browser.
Gateways come in many forms and variants, either as hardware or as software modules.
Some systems take the inconvenient approach of trying to combine as many gateways as possible into a single "universal gateway" device. This often results in the end user paying for unnecessary features and/or devices functioning unstably and prone to failures. Having a dedicated gateway for each protocol is much more elegant and allows the full functionality of each communication channel to be utilized without restrictions, as bandwidth and other parameters are tailored specifically.
Here is a list of protocols and manufacturers that can be connected today. Devices from different manufacturers can then communicate, for example, using the KNX medium. (Of course, many more options exist, but covering them all would go beyond this scope.)
Z-Wave, ZigBee, EnOcean, Bluetooth, Homematic, Wi-Fi, DALI, CAN, LON, M-BUS, RS232, RS485, TCP/IP, IoT (Alexa, Sonos, etc.), HTTP, MQTT, SNMP, DMX, MODBUS, BOSCH 4A, 1-Wire, effeff BCM925, EsserNet, Honeywell MB100.10, Warema, Somfy, Hue, Hörmann, Velux, Daikin, Becker, ekey, AMX, Crestron, Panasonic, Axis, Berbel, Miele, etc.
In addition, various software concepts can perform similar functions on platforms like a Raspberry Pi, such as IPSymcon, SmarthomeNG, Openhab, FHEM, ioBroker, HomeKit, and others. These software solutions take the path of total control and sit on top of the system, monitoring, managing communication, and enhancing it with logic functions. The downside is that if the server fails, the entire system usually goes offline and becomes operable only manually. In decentralized systems, a complete failure almost never occurs (except during a power outage, which can also be mitigated), making the risk of total failure much lower.