When you work with something every day, it’s easy to assume that everyone knows what you’re talking about. That applies to IHT (Integrated Home Technology). We spend a lot of time working with people in the industry and we sometimes speak our own language of technical terms and long strings of initials that don’t mean much to anyone outside the field.
To make things easier for anyone just taking an interest in this technology, from time to time this blog will be looking at some of the technical terms and industry brand names that we deal with every day. We hope this will make it easier when you are trying to decide what system is right for you.
We’re going to start today with some of the terms that relate to how different devices communicate with each other.
Infra-red (IR): In scientific terms, light that is below the spectrum of Human Vision, therefore invisible. Many people mistakenly think infra-red lights is red, because visible red light is added as a safety feature on IR warming lamps used in restaurants. Most modern televisions and Audio Video Appliances utilize infrared remote controls to transmit infrared light to a receiver hidden behind the face of the appliance to control, audio, channel selection and other functions. It’s a cheap and easy way to control things, but it isn’t good at giving feedback on the status of device and you need to be able to see the device you’re controlling. Many inexpensive “touch screen systems” are actually just universal infra-red remotes in a fancy package. When someone promises to “control everything” for a hundred dollars, odds are you are getting a fancier version of the hand-held remote that came with your TV. Infra-red can still be useful in some home technology systems, but its technical limits have made it less popular.
RS-232 and RS-485: When people started connecting different devices together, they realized ti would be a good idea if they spoke the same language. As a result, they came up with Recommended Standards (RS) for the type of signals they send each other. It sets a standard for how much voltage, what kind of cable and how messages will be sent after they are broken down in a string of one’s and zeros. RS-232 was the first, but as systems became part of complicated networks, the higher RS-485 standard was added. It was designed to handle multiple devices. Because of these standards, equipment from different manufacturers can communicate seamlessly. RS signals have been especially popular for controlling devices like data/video projectors and professional quality audio equipment.
Radio Frequency (RF): To a scientist, Radio Frequency is just another form of electricity. It just happens to be kind of electricity that can be sent from an antenna in invisible waves. Because of that, it’s useful for sending all kinds of signals from place to place. Some of the uses are for radio (AM and FM), but RF is also used to send TV signals, satellite communications, and in cordless and cellular phones and wireless microphones. RF is important in Integrated Home Technology, as it can be used both in wireless remotes controls and as a way to send information about lights and other systems around the house without running cables. It can also go through walls and around corners, something Infra-red can’t do.
Ethernet: Way back in 1973, a Xerox employee name Bob Metcalfe realized that computerized systems were going to need a way to connect and talk to each other. You now use what he invented every single day. He developed the concept of ethernet. Ethernet isn’t actually a single thing. It’s a set of standards for hardware, cables, connectors and anything else on a computer network, and because everyone uses that standard it that makes sure everyone’s equipment is on the same page. His design has been adopted worldwide. If you have internet in your house, the cable that brings it in and the connector that plugs into your computer are based on his design. In home automation, we have discovered that this type of cable and this way of sending information is incredibly efficient and powerful. By using this type of connection, we are able to send enormous amounts of information and signals to control devices and do it over small inexpensive cables.
CAT-5: You will hear this term used a lot. It refers to wire used for computer signals. The wire industry has different categories of wire. This one is Category 5. It’s simply a cable with four pairs of twisted copper wire inside. When it was introduced, it could carry virtually any computer signal 100 metres. As demands grew to send even more information down the wire, Category 5e came out (CAT-5e). It can carry more information and over a longer distance. Now Category 6 is being used to carry even more information. In Integrated Home Technology, Category 5, 5e and 6 wire is often used to carry video and control signals. It’s perfect for home use because it’s small, cheap, and carries an incredible amount of data over long distances. That means lower cost and fewer hole in the walls and the ceiling when a system is installed.
That’s of for this week. We’ll come back to this from time to time as we try to help you become an educated user of Integrated Home Technology.