The Essential Components for Every Automation System

Automation systems have been imperative to industrial progress for decades, ranging in scale from simple conveyor lines to an entire manufacturing facility. Modern setups are continuing to grow in complexity and specialization, but there still remains a set of parts that are absolutely central to making any industrial or general automation system work. This blog will explore many of these core elements, helping those interested in designing an effective automation system understand the building blocks required.

Core Control Components

Programmable Logic Controllers (PLCs)

A PLC serves to receive information from the physical world, process logic based on programmed instructions, and then issue commands to control various devices. They vary in their intricacy and components employed, but a typical PLC system will be made up of:

• Central Processing Units (CPUs): The CPU executes control logic and determines output signals based on input data.
• Input/Output (I/O) Modules: I/O modules are the interface between the PLC’s internal logic and the external inputs/outputs of other components in the system.
• Memory / Program Storage: Memory or program storage retains the control program and operational data, allowing the PLC to preserve its instructions and system state.
• Backplanes / Racks / Chassis: The backplane, rack, or chassis forms the structural framework of the PLC system and incorporates an internal bus that distributes both data and power to all installed modules.
• Power Supplies: The power supply converts incoming AC or DC mains voltage into the regulated DC voltage that is required by the CPU, I/O modules, and other internal circuitry, which is usually 24 V DC or lower.

Because of their modular design, more I/O modules can be added as needed, and other upgrades or expansion can take place without replacing the entire system.

Other Control Options

While PLCs are widely used, they are not the only option available. When flexible programming environments or high computational power are needed, ruggedized computers known as industrial PCs are able to run full operating systems and execute sophisticated software like SCADA systems, machine vision algorithms, real-time analytics, or custom control applications. Additionally, for compact machines or cost-sensitive equipment where a full programmable controller would be unnecessary or impractical, control functions can also be handled by embedded controllers or microcontroller-based boards.

Perception Devices

As we briefly mentioned, intelligent responses to the environment or ongoing processes are a central enabler of automation. This largely falls on sensors, with two of their most prominent categories being object detection and process measurement variants.

Object Detection Sensors

Object detection sensors identify the presence, absence, or movement of items within an automated environment, including common options like:

• Proximity Sensors: Proximity sensors detect nearby objects without physical contact. For example, capacitive proximity sensors are able to detect materials by measuring changes in capacitance. Meanwhile, ultrasonic proximity sensors emit sound waves and measure reflections to detect objects regardless of color or transparency.
• Photoelectric Sensors: These sensors use a light emitter and receiver to detect an object breaking or reflecting a light beam.
• Limit Switches: Limit switches are electromechanical switches that detect physical contact with an object, serving end-of-travel detection and position verification.

Process Measurement Sensors

Process sensors measure physical variables, with regularly-relied upon types including:

• Pressure Sensors: Pressure sensors measure gas or liquid pressure using strain-gauge, piezoelectric, or resonant sensing elements.
• Temperature Sensors: Temperature sensors monitor thermal conditions in equipment or processes. Two major types are thermocouples, which generate a voltage based on the temperature difference between two dissimilar metals, and Resistance Temperature Detectors (RTDs), which determine temperature by measuring the change in electrical resistance of a metal element.
• Level Sensors: Float switches, capacitive level sensors, and ultrasonic level sensors are common subtypes of level sensors that determine the height or presence of liquids or bulk solids in containers.
• Flow Sensors: Flow sensors measure the flow rate of liquids or gases in pipelines, coming in many different variants.

Action Devices

Actuators and other such output devices deliver the physical result of control logic, coming in many forms.

Motors

Motors generate controlled rotational or linear motion for machinery like conveyors, robotic arms, printing mechanisms, and other such positioning systems. In automation setups, these typically include:

• AC and DC Motors: AC motors are valued for continuous, high-duty industrial applications due to their efficiency and relatively simple construction, while DC motors offer smoother speed control and are used where variable or low-speed operation is desired.
• Servo Motors: Servo motors incorporate feedback systems that allow fine control of position, speed, and torque, serving automated positioning tasks like robotics and CNC machinery well.
• Stepper Motors: Stepper motors move in precise, incremental steps without requiring continuous feedback.

Hydraulic and Pneumatic Cylinders

Converting pressurized fluid into linear movement or force, hydraulic cylinders are used when great force is required, such as in presses or heavy-duty handling equipment. On the other hand, pneumatic cylinders use compressed air for action and are well suited for faster, repeated operations, as well as setups that cannot afford the risk of contamination from fluid leaks.

Solenoid Valves

Solenoid valves control the movement of air, liquids, or gases within a process system, utilizing an electrical signal to energize a coil that shifts the valve’s internal mechanism. This action opens or closes the flow path, allowing systems to regulate routing and maintain pressure levels.

Purchase Building Blocks for Automation on ASAP Industrial Services

Whether you are considering implementing a new automation installation or planning to upgrade an existing system, having a basic understanding of the core components that drive their functionality is vital. If you are looking to source any of these parts or others to create a self-regulating system, turn to ASAP Industrial Services for top-notch options.

As an ASAP Semiconductor owned procurement platform, we understand the importance of sourcing products that will hold up for years to come. Within our inventory, we feature a wide range of quality-assured industrial automation, general automation, and circuit board parts from trusted manufacturers. To learn more about our services and offerings, be sure to check out our website and connect with our experts via phone or email today.