A Programmable Logic Controller (PLC) receives information from one or more inputs. This semiconductor control device processes the information based on a software program. Finally, it sends an output control signal. The microprocessor based control system performs functions such as timing, logic, sequencing and others. The PLC follows instructions from an operator-defined program.

These intelligent systems provide reliable, high-speed monitoring and control of processes in automated applications. In addition, they are easy to program and configure.

Once the program updates the output, the CPU starts over and the cycle repeats again. The cycle depends on the number of inputs, outputs, and size of the program, while the action will depend on the inputs coming from a variety of sensors.

The input sensors include components such as switches, proximity sensors, photoelectric sensors, pressure switches, level switches, encoders and temperature sensors, while the output devices include actuators, relays, switches, and many more.

PLCs rely on software programs that help them in making the necessary decisions. The PLCs are programmed through a variety of tools, which may differ in ease of use, appearance, and complexity. The most commonly used PLC programming language is Ladder Logic, a graphical software that uses common electrical symbols. Other languages include Function Block Diagram (FBD), Sequential Function Chart (SFC) and Structured Text (ST).

The programming is done on the device such as a computer or handheld device after which it is transferred to the PLC memory using a communication interface.

Selecting a suitable PLC that will address your current and future needs can be a challenge, especially with the large number of different PLCs on the market today. The available PLCs have varying capabilities, physical sizes, complexity, cost, power requirements, scalability and other parameters. Therefore, it is necessary to determine the correct programmable logic controller for your specific application. Special systems can be designed for use in harsh environments.

The Programmable Logic Controller has revolutionized and simplified controls in automation and industrial applications. PLCs are easy to install, wire, program and modify to suit changing application requirements. These control systems are usually available in a wide range of sizes that ensure finding exactly what you need for any application.

Smart technology is poised to take over the home appliance market. We already have smart thermostats, smart lighting and even smart refrigerators. If that's not enough for you, there are some new contenders on the market that allow you to turn any electrical device in the home into a smart item. The best part is that it's a simple DIY experience – no need to find an electrician to hook it up. It’s the smart plug, a small box that you plug into your home's outlets. From there, you can use your smart phone to control whatever light, television or other electronic appliance routed through the smart plug. Read on to learn more about these remarkable efficiency devices.

Control and Monitor Your Electronics

There are a variety of smart plug options on the market: The Satechi IQ Plug, the Belkin WeMo Insight Switch, the D-Link Wi-Fi Smart Plug and the Valta Starter Kit, among others. The cost and functionality of the different brands vary, but they all operate on a similar principle – allowing you to set schedules and remotely control whatever device you choose.

The smart plugs connect to your phone via Bluetooth or wireless Internet, so you can switch them on or off from anywhere in the home – or even from the other side of the country if you have an internet-optimized model. You can also program schedules so the plug automatically activates an appliance at appointed times – turning a coffee maker on first thing in the morning, for example, or switching on a space heater before you go to bed in a chilly part of the house.

Retro Meets Modern

The upshot is that there's no need to wait for cutting-edge smart devices to come out to keep your home on the cutting edge of technology. Imagine impressing your neighbor by demonstrating the new smart functionality of a retro 1950s television, or your old Victrola vinyl player.

Smart plugs also monitor how much electricity a given device uses and when, so you can make informed choices about increasing your energy efficiency though disaggregation, breaking it down appliance by appliance. You can also save energy by using the smart plug to turn off the power to devices when you aren't actively using them, preventing your electricity bills from skyrocketing due to always-on settings or “energy vampires.”

Savings and Control All at Once

If you have additional questions about smart plugs and how they work, find an electrician who can show you their utility and functionality. With surprisingly little effort, you can harness their power to save energy and control devices all throughout your home.