Automation and Control Guides Page 8: 198 technical guides for choosing Automation and Control products: selection criteria, standards, common mistakes and frequently asked questions.
Spring-Return Push Buttons Selection Guide — When selecting spring-return push buttons, compare Ø22 mm mounting diameter, NO/NC contact blocks, illuminated vs non-illuminated heads and IEC 60204-1 color coding. Pilot Lights, Buzzers, and Signaling Equipment Selection Guide — How to select Ø22 mm LED panel pilot lights, acoustic-visual buzzers, and signaling accessories by voltage (24V / 220V), IEC 60073 color codes, and IP rating. Control, Timer, and Safety Relays Selection Guide — How to select time-delay relays, star-delta timers, liquid level control relays, safety relays, and astronomical time switches for industrial panels. Measuring and Control Devices Selection Guide — Selection guide for panel-mount multimeters, energy meters, ammeters, voltmeters, PID temperature controllers, temperature probes and digital counters. PLC Input and Output Modules Selection Guide — Engineering guide to choosing PLC digital I/O, analog 0–10 V / 4–20 mA, RTD/thermocouple temperature, load cell and fieldbus communication expansion modules. Control Push Buttons, Switches and Pedals Selection Guide — Selection criteria for Ø22 mm push buttons, emergency stop switches, selector switches, joysticks, control boxes and foot pedals by NO/NC contact configuration and voltage. What is the difference between a PT100 (RTD) and a thermocouple? — Compare PT100 resistance temperature detectors (RTD) and Type J/K thermocouples by temperature range, accuracy, wiring compensation and industrial use. What is the difference between a solid state relay (SSR) and a contactor? — Compare semiconductor SSRs and electromechanical contactors across switching frequency, PID temperature control, acoustic noise and thermal dissipation. Thermostat and Temperature Controller Selection Guide — A temperature controller compares the temperature read from a sensor with the set value and drives a heater or cooler; a selection and sensor guide. What Is an Electricity Meter? Energy Meter Selection Guide — An electricity meter measures and totals the electrical energy passing through a circuit in kWh; this guide covers connection current, communication, tariff and accuracy class. What Is a Sensor? Industrial Sensor Types and Selection — An industrial sensor detects the presence or position of an object and signals a control device; inductive, capacitive and photoelectric types are available. What Is an HMI? Operator Panel Selection Guide — An HMI is an industrial interface device that lets an operator monitor a machine on screen and control it through the PLC; this guide covers PLC compatibility, ports and screen selection. What Is SCADA? Industrial Automation Software Guide — SCADA is a supervisory system that monitors many PLCs and devices. Review Plant SCADA, AVEVA Edge and InTouch license types, tag counts and selection criteria. What Is a Photocell? Photoelectric Sensor Selection Guide — A photocell is a sensor that detects interruption or return of light from an object and gives a contactless output; find its types and selection criteria in this guide. What Is a Relay? Types and Selection Guide — A relay is a switch that opens and closes the contacts of a separate circuit with a low-power control signal. Types, coil voltage and contact selection are covered here. What Is a Frequency Inverter? Drive Selection Guide — A frequency inverter is a drive that adjusts the speed and torque of an induction motor by changing the output frequency; see the selection criteria and drive types. What Is a PLC? Types and Selection Guide — A PLC is an industrial control computer that processes sensor signals according to a program and drives outputs; a guide to selecting CPUs, mini PLCs and modules. Servo Motors Selection Guide — A servo motor is a motor whose position, speed and torque are precisely controlled through encoder feedback and a servo drive. It is selected by torque, speed and drive compatibility. Potentiometers Selection Guide — A potentiometer is a three-terminal voltage divider; it comes in analog and digital types, and for analog, resistance, number of turns and wiring decide the choice. What Is an Ammeter? Types and Selection Guide — An ammeter is a measuring instrument that shows the electric current flowing through a circuit in amperes, and it is connected in series with the circuit being measured. This guide covers panel-mount models, the AC-DC distinction and current transformer selection. Voltmeters Selection Guide — A voltmeter is an instrument that shows the voltage between two points in volts; for panel-mount models, the number of phases, range, supply and size decide the selection. Emergency Stop Buttons Selection Guide — Emergency stop buttons come in twist-release, pull-release, key-release, illuminated and enclosed types; choose by release method and mounting location. Inductive Sensors Selection Guide — An inductive sensor is a proximity sensor that detects metal objects entering its electromagnetic field without contact. Sensing distance is chosen by housing and output type. Encoder Selection Guide — An incremental encoder generates pulses on A and B channels 90° out of phase as the shaft turns; when choosing, calculate resolution (ppr) and accuracy.