Taking advantage of Modbus interfacing systems at home and at your fingertips
Or how an old technology may be the best solution
September 30, 2008 Version 1 in production. Now on the way to V3.0
In the not too distant past, as children we invented the future thinking of domestic spaceships, swift cars without wheels, and robotic homes that made life easier for us. Time passed and the supposed home automation revolution that we all hoped for, brought us a lot of technologies incompatible with each other at a price that was only within reach of a handful of privileged people. There is currently no home automation standard. Instead the manufacturers compete trying to place their products, taking advantage of the ignorance of the average domestic user.
In 1979, Bedford Associates developed a new generation of modular digital controllers easily manageable by a transmission protocol named Modbus, designed for the complex electronic industrial devices of the time. Soon Modbus became a widely accepted standard in the world of controllers, both at industrial level and nowadays in the new world of small consumer devices, with reasonable costs and produced by a wide variety of manufacturers.
The concepts Modbus and SCADA have always been closely related. SCADA is a design philosophy of industrial control systems based on the feedback information provided by different sensors contributing in the management of other devices under control. The industrial level of the SCADA architectures has kept it apart from a world as seemingly different as any modern home. However, after this first approach it’s possible to discover that there are actualy many similarities between a complex industrial machinery and the activities we routinely carry out at home. So we turn on a bulb in the living room when we need to read a book, but if it’s a sunny day and we can count on the light of the sun, we open the blind.
Dreaming about our home
What would our life be like if we only had to turn on that switch to get light? So we could leave for our house the decision to choose the best way to enlighten us. If there is sun outside, opening the blinds, if not, turning on the next bulb (or bulbs) over us, but. What light ?. Depending on our need, the time of day and the weather, our house would make the right decision, taking into account the very current fare of electric energy, indoor and outdoor temperature, our situation in the room and the amount of light on the outside, all several times per minute. If we enjoy the sunlight and our book is so interesting that it becomes night, the house will turn on a light and close the blind when it is the best time to do so. The result is that we would have light, as in a normal house but at the same time would be the cheapest light, the most appropriate, the healthiest and also the most ecological.
Your Home as a Doll House
What if you could see our home as a whole and understand everything that happens in it?
Even those old fashioned switches would not be the same as before. With a simple modification (XML file) in the system configuration any switch could be dedicated to any other function, from turning on the nearest bulb to opening the blind, but also warning of your presence, connecting the air conditioner, turning off the stereo sound, sending an email or even activating the heating of your car. The more conservative people would not notice the change, they would not even notice that little delay on the light fade, but they would appreciate it because they keep the light on seconds makes things easier
Is no matter of the complexity but the result, and nobody will know exactly where rests the magic, just that it is there.
Open and Live
The configuration of each home is contained in just two XML files. One for the description of the installed controllers and the devices that depend on them and another containing the list of operational modes, wich is where the behavior of the system under each possible situation is defined. Being editable files, any user with elementary knowledge can expand and improve your house according to your preferences, budget and possibilities, adding drivers and defining behaviors. The limit is only the imagination. Installing the drivers is easy. Any electrician with average knowledge can do it safely. All the modbus controllers are available in a large variety of online distributors and prices all over the world. The growth of an open system as this is unlimited, as well as the useful life of the home automation which is enriched with the incorporation and update of all the devices under control. As simple as buying a new lamp… The domotics part of the home will evolve with its owner, improving its quality of life and increasing the value of the property.