In digital computers, an interrupt is a request for the processor to interrupt currently executing code, so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an interrupt handler to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error.
A logic gate is a device that performs a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has, for instance, zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device.
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity that requires high reliability, ease of programming, and process fault diagnosis.
A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof.
Digital electronics is a field of electronics involving the study of digital signals and the engineering of devices that use or produce them. This is in contrast to analog electronics which work primarily with analog signals. Despite the name, digital electronics designs includes important analog design considerations.
An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use. In 2009, it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems.
Ladder logic was originally a written method to document the design and construction of relay racks as used in manufacturing and process control. Each device in the relay rack would be represented by a symbol on the ladder diagram with connections between those devices shown. In addition, other items external to the relay rack such as pumps, heaters, and so forth would also be shown on the ladder diagram.
Automation describes a wide range of technologies that reduce human intervention in processes, mainly by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines. Automation has been achieved by various means including mechanical, hydraulic, pneumatic, electrical, electronic devices, and computers, usually in combination. Complicated systems, such as modern factories, airplanes, and ships typically use combinations of all of these techniques. The benefit of automation includes labor savings, reducing waste, savings in electricity costs, savings in material costs, and improvements to quality, accuracy, and precision.
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines. The control systems are designed via control engineering process.
A cam timer or drum sequencer is an electromechanical system for controlling a sequence of events automatically. It resembles a music box with movable pins, controlling electrical switches instead of musical notes.
A real-time clock (RTC) is an electronic device that measures the passage of time.
A motor controller is a device or group of devices that can coordinate in a predetermined manner the performance of an electric motor. A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque, and protecting against overloads and electrical faults. Motor controllers may use electromechanical switching, or may use power electronics devices to regulate the speed and direction of a motor.
A stopwatch is a timepiece designed to measure the amount of time that elapses between its activation and deactivation.
A sprinkler system timer is an electrical device that is used to set an irrigation sprinkler system to come on automatically at a certain time. Irrigation timers first appeared in the early 1960s to control large-radius lawn sprinklers, which at the time usually contained their own electrically operated valve. These timers were large and cumbersome with numerous mechanical parts and were usually relegated to agricultural and commercial applications. Compact irrigation timers did not become commonplace until the 1970s when Lawn Genie introduced a mechanical timer which measured only ten by six inches and was four inches deep. This controller proved popular for many years, but was hard to reprogram and it did not operate valves in immediate succession unless each valve was set to run for an hour. Rain Bird later introduced the RC-7A to their Rain Clox line, which featured an "at a glance" electromechanical programming interface that proved very easy to operate, and offered the ability to omit stations from the program sequence without creating time gaps. This timer which became standard issue in many tract homes during the 1980s and proved to be remarkably durable in its construction, with many still operating today.
In engineering, hardware architecture refers to the identification of a system's physical components and their interrelationships. This description, often called a hardware design model, allows hardware designers to understand how their components fit into a system architecture and provides to software component designers important information needed for software development and integration. Clear definition of a hardware architecture allows the various traditional engineering disciplines to work more effectively together to develop and manufacture new machines, devices and components.
The following outline is provided as an overview of and topical guide to automation:
A time switch is a device that operates an electric switch controlled by a timer.
The following outline is provided as an overview of and topical guide to electronics:
Windows Clock is a time management app for Microsoft Windows, with five key features: alarms, world clocks, timers, a stopwatch, and focus sessions. The features are listed on a sidebar. The app is similar in functionality and design to the Clock app on iOS. Windows Clock was available on mobile devices for over a decade before it was available on PCs with the introduction of Windows 8.1. Tiles for alarms, timers, and the stopwatch can be pinned to the Start menu. The latest version of the app uses the Universal Windows Platform APIs and adopts Windows UI theme. Windows Clock is distinct from the Windows taskbar's clock, which has been part of Windows since 1995.
A photo-lab timer,photo interval timer, or darkroom timer is a timer used in photography for timing the process of projecting negatives to photosensitive paper with an enlarger, making photographic prints of them at any scale. It is a device which is attached to the photo lab enlarger to ensure that the duration of photo exposures on sensitive paper can be accurately timed. When the selected time has elapsed, the enlarger is switched off or an alarm is sounded, for the photographer to turn it off.
