Many small electronic components operate from low-voltage DC power, frequently 12, 24, or 48 volts. A Power Supply converts incoming AC power (such as 115VAC from a wall outlet) into DC for use by these devices. Power Supplies are rated by the output voltage and current, and are most often DIN-rail mounted inside a control panel.
A Relay is an electrically operated switch – most commonly electro-mechanical, but options also exist for solid-state. A low-power signal operates the coil, which then engages the contacts and transmits power the end device. Many options exist for numbers of poles and throw configurations, as well as time-delay relays, latching relays, and other functions – even including programmable logic actions in the specific case of “Smart Relays”. When switching power directly to a motor, a Relay is known as a Contactor.
Panel Meters perform a variety of functions, frequently including temperature (or general PID process) control, timing, counting, or just indication to a user of some process variable or setpoint. Panel Meters are common to many types of automated systems and can be very cost-effective compared with a small PLC and Operator Interface for simple functions.
Radio-Frequency IDenification (RFID) is a technology that allows for wireless communications between a tag and reader, commonly used for inventory tracking or component identification to a control system.Various frequencies of operation exist for different purposes, and tags may take any number of forms, such as ID badges, key chains, printed flat labels, and many others.
A fully populated Control Panel consists of all a machine’s electrical/electronic hardware inside an enclosure – for example, the PLC, drives, power supply, an operator interface, and all the wiring and accessories that go along with them and alloWthem to function. Frequently this involves circuit breakers or fusing for branch circuit protection, terminal block for wiring, disconnect switches, safety relays, connectors for quick wiring to external sensors/motors/etc., and more.