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.

Our electrical system runs behind the walls and in our ceilings and floors. It is invisible, except for outlets and fixtures. Electricity is intrinsically counter-intuitive to think about. In fact, despite recent technological developments, we’ve only known how electricity works since the turn of the 20th century. So, you can be forgiven if even common residential electrics seem somewhat mysterious. Moreover, repairing these electrical systems requires the professional knowledge of a Kirkland electrician, who knows how to properly handle and harness electrical energy and run it safely through your home. In this post, we’d like to examine a few of the most common electrical repairs, so that you might be able to identify any problems and call for assistance.

My wife and I are the happy parents of a sixteen-month-old boy. Having a kid has turned out to be every bit as wonderful and exhausting as our family and friends told us it would be. We can see why everyone we knew with children, including our own parents, told us with that knowing smile, “Your life will never be the same.” They were right. There’s never a dull moment, is there? Every day presents new challenges and responsibilities.

For example, a couple hours ago, my son was screaming at his grandma for taking a bite of his banana. Nap time soon? Sheesh.

3. Use an In-Wall Night Light

Instead of that old incandescent night light just begging to be pulled out of the wall by your young one’s inquisitive hands, consider a safer and greener alternative. LED night lights will safen and cozy-up baby’s room in elegant and energy-smart fashion.

I have a great deal of interest in digital photography, but my life is as crazy as anyone else’s. My son, family, and work keep me busy from dawn to midnight every day. I’ve never had time to cultivate any photography skills, even though I’ve always been very interested, sitting on the edge of my seat, if you will, for a chance to take some digital photos in order to learn a little about how capturing light can create astonishing works of art.

My interview with Matthew Danser had given me my long sought “excuse” to try out some photography techniques. But it also required that I put in an honest effort. The thought in the back of my head: These photos are going to suck. Probably a lot. And they will most likely be seen by the thousands of people who visit this blog monthly. Second gulp.

But I’m the kind of person so riddled with ADHD that even my paranoia about being judged on a mass scale can only last about three minutes before the audacity to try anything resurfaces and action is taken. So here’s what happens when a total amateur who has no idea what he is doing tries to “Paint with Light.”

A one-dollar flashlight from – you guessed it – the Dollar General. One dollar. Even. Gotta love it. Especially since it’s all I could afford, seeing as how I’m still paying off the aforementioned Nikon that I bought to take photos of our baby son. (True, a million pictures have been taken of him during his first year-and-a-half on Earth. However, 999,999 of those photos were taken with an iPhone. Go figya.)

THE PLAN, STAN:

The plan was to wait until it was dark in the apartment and do some light painting. I knew that I could use the Shutter mode on my camera to set it to take exposures of up to thirty seconds. I saw that my camera also had an option for bulb release, so, invoking Danser, who recalls how his girlfriend had to hold down the button on his camera for a full thirteen minutes, I determined that if I asked really nicely, I might be able to persuade my wife to hold down the trigger to get exposures longer than thirty seconds. Otherwise, thirty seconds was my window of time to do all the light painting I could.

I started off pretty timidly. I had seen photos online in which people used long exposures to create squiggly lines. The most popular examples are pictures of traffic at night, headlights and tail lights streaming, giving you a sense of the fluid motion of busy intersections. You’ve also seen those nature pics in which streams and rivers and clouds and stars become gauzy with movement because of long exposures.

But what I really like about Danser’s work is the use of color. The effect of running inside the hut and popping off red-gelled flashes shown at the beginning of this blog post (Matthew Danser! And happy lightpainting, everyone!