Essential Categories Every Automation Engineer Must Know
Industrial automation encompasses a vast ecosystem of equipment working together to control, monitor, and optimize manufacturing processes. Whether you are new to the field or looking to expand your knowledge, understanding these core categories—and the leading manufacturers in each—will help you make informed decisions for your projects.
1. Controllers: The Brain of Automation Systems
Programmable Logic Controllers (PLC)
PLCs are the workhorses of discrete manufacturing, handling logic-based control for assembly lines, packaging machines, and material handling systems.
| Brand | Popular Series | Strengths | Best For |
|---|---|---|---|
| Siemens | S7-1200, S7-1500 | Excellent integration with TIA Portal, strong networking | Complex systems requiring seamless HMI integration |
| Allen-Bradley (Rockwell) | ControlLogix, CompactLogix | Robust ecosystem, excellent North American support | Automotive, food & beverage industries |
| Mitsubishi | iQ-R, FX5U | High-speed processing, compact design | High-speed packaging, semiconductor |
| Omron | NX/NJ Series | Machine automation focus, EtherCAT native | OEM machine builders |
| ABB | AC500 | Scalable architecture, strong process integration | Hybrid applications |
The Siemens 6ES7512-1CK01-0AB0 CPU Module exemplifies modern PLC design with integrated safety and motion capabilities. For ABB systems, the PM851 Controller Module offers excellent scalability.
Distributed Control Systems (DCS)
DCS platforms excel in continuous process industries where analog control and regulatory loops dominate.
| Brand | Platform | Strengths | Best For |
|---|---|---|---|
| ABB | Symphony Plus, 800xA | Excellent batch control, strong power industry presence | Power generation, pulp & paper |
| Honeywell | Experion PKS | Advanced process optimization, cybersecurity focus | Refining, petrochemical |
| Yokogawa | CENTUM VP | Highest reliability ratings, excellent analog control | Chemical, LNG |
| Emerson | DeltaV | Easy configuration, strong batch capabilities | Pharmaceutical, specialty chemical |
| Siemens | PCS 7 | Seamless PLC integration, unified engineering | Hybrid manufacturing |
The ABB DSDO115 Digital Output Module serves Symphony DCS installations, while Yokogawa SCP451-11 Processor powers CENTUM systems.
Industrial PCs (IPC)
IPCs bridge IT and OT worlds, running Windows or Linux-based control software with standard computing architecture.
Leading IPC manufacturers include Siemens (SIMATIC IPC), Beckhoff, Advantech, and B&R. These systems excel in vision-intensive applications, data logging, and edge computing scenarios where standard PLC programming is insufficient.
2. I/O Modules: Connecting the Physical World
I/O modules translate between field devices and controllers, handling digital signals (on/off) and analog signals (4-20mA, 0-10V).
| Type | Function | Common Applications |
|---|---|---|
| Digital Input | Read switch/sensor states | Limit switches, proximity sensors, push buttons |
| Digital Output | Control discrete devices | Solenoid valves, indicator lights, relays |
| Analog Input | Read process variables | Temperature, pressure, flow, level |
| Analog Output | Control proportional devices | Control valves, variable speed drives |
Remote I/O systems like the Bachmann BS206 I/O Bus Coupler reduce wiring costs by placing I/O near field devices. The ABB AI623 Analog Input Module provides high-resolution process measurement for demanding applications.
3. Drives and Motion Control
Variable Frequency Drives (VFD)
VFDs control AC motor speed and torque, delivering energy savings of 20-50% in pump and fan applications.
| Brand | Popular Series | Strengths | Best For |
|---|---|---|---|
| ABB | ACS880, ACS580 | Direct torque control, excellent motor protection | Heavy industry, cranes |
| Siemens | SINAMICS G120, S120 | Seamless PLC integration, safety functions | Machine building, process |
| Danfoss | VLT Series | HVAC optimization, robust design | Building automation, water/wastewater |
| Yaskawa | GA700, GA500 | High overload capacity, compact size | Material handling, packaging |
| Schneider | Altivar Process | Built-in process PID, asset management | Pumping, HVAC |
The ABB ACS355 Frequency Converter delivers reliable motor control for general-purpose applications. For drive control boards, the RMIO-01C CPU Board provides the intelligence behind ABB drive systems.
Servo Systems
Servo drives and motors provide precise position, velocity, and torque control for demanding motion applications.
| Brand | Strengths | Best For |
|---|---|---|
| Yaskawa | Industry-leading tuning, high bandwidth | Robotics, CNC |
| Fanuc | Exceptional reliability, CNC integration | Machine tools |
| Mitsubishi | Compact design, fast response | Semiconductor, electronics |
| Siemens | Integrated safety, TIA Portal | Packaging, printing |
| ABB | Robust construction, process integration | Heavy industry |
The ABB SYN5012a-P AC Servo Drive handles demanding motion control applications. For GE turbine systems, the IS220PSVOH1A Servo Control Module provides precise valve positioning.
Stepper Systems
Stepper motors offer cost-effective positioning without feedback in applications where missing steps is acceptable. Oriental Motor, Applied Motion, and Leadshine dominate this segment, with typical applications including 3D printers, CNC routers, and pick-and-place machines.
4. Sensors and Detection Equipment
Temperature Sensors
RTDs offer high accuracy (±0.1°C) for process control, while thermocouples handle extreme temperatures up to 1800°C. Leading brands include Endress+Hauser, Rosemount (Emerson), and WIKA.
Pressure Transmitters
Modern smart transmitters provide 0.04% accuracy with HART or Foundation Fieldbus communication. The ABB 3BHE040375R1010 Pressure Transmitter delivers reliable measurement for process applications.
Level Sensors
Technologies include radar (non-contact, handles vapor), ultrasonic (economical), guided wave radar (interface measurement), and capacitance (simple liquids). Endress+Hauser, VEGA, and Siemens lead this category.
Flow Meters
Electromagnetic flowmeters dominate conductive liquid measurement, while Coriolis meters provide mass flow and density. Endress+Hauser, Emerson (Micro Motion), and Yokogawa are market leaders.
Position and Motion Sensors
Encoders convert mechanical position to electrical signals. The ABB CD522 Encoder PWM Module interfaces encoders with control systems. Proximity sensors from Sick, Balluff, and IFM detect object presence without contact.
Vision Systems
Machine vision performs inspection, measurement, and guidance tasks. Cognex and Keyence dominate with smart cameras, while Basler and FLIR provide industrial cameras for custom solutions.
5. Human-Machine Interface (HMI)
HMIs provide operators with visualization and control of automated processes.
| Brand | Popular Series | Strengths | Best For |
|---|---|---|---|
| Siemens | Comfort Panels | TIA Portal integration, industrial design | Siemens PLC systems |
| Allen-Bradley | PanelView Plus | FactoryTalk integration, robust | Rockwell ecosystems |
| Pro-face | GP4000 | Multi-protocol support, reliability | Multi-vendor environments |
| Weintek | cMT Series | Excellent value, cloud connectivity | OEM machines, cost-sensitive |
| ABB | CP600 | AC500 integration, web visualization | ABB control systems |
The ABB PP865 Touch Screen Panel provides advanced visualization for 800xA systems. For compact applications, the ABB CP604 Touch Screen offers cost-effective operator interface.
6. Communication and Networking Equipment
Industrial Ethernet Switches
Unlike office switches, industrial switches handle extreme temperatures, vibration, and EMI while supporting deterministic protocols.
| Brand | Strengths | Best For |
|---|---|---|
| Cisco (IE Series) | Enterprise integration, cybersecurity | Large facilities, IT/OT convergence |
| Hirschmann | Redundancy protocols, rugged design | Process industries, rail |
| Moxa | Wide temperature range, serial connectivity | Remote sites, transportation |
| Siemens (SCALANCE) | PROFINET optimization, TIA integration | Siemens automation systems |
Protocol Gateways
Gateways translate between protocols (Modbus to Ethernet/IP, PROFIBUS to PROFINET). The ABB CI840 Field Communication Interface connects diverse field devices to AC 800M controllers.
Fieldbus Equipment
Legacy fieldbus networks (PROFIBUS, DeviceNet, Foundation Fieldbus) remain common. The Siemens 6ES7972-0BB52-0XA0 PROFIBUS Connector provides reliable network connections.
7. Power Supply and Protection Equipment
DC Power Supplies
24V DC is the standard for industrial control circuits. Key selection factors include output power, efficiency, and form factor.
| Brand | Strengths | Best For |
|---|---|---|
| Phoenix Contact | QUINT reliability, diagnostics | Critical applications |
| PULS | Highest efficiency, compact | Space-constrained panels |
| Siemens (SITOP) | TIA integration, wide range | Siemens systems |
| Mean Well | Excellent value, availability | Cost-sensitive, general purpose |
| ABB | CP-S series reliability | ABB control systems |
The ABB SA610 Power Supply Module provides reliable power for automation systems. For backup power, the SB510 Backup Power Supply maintains operation during outages.
UPS Systems
Uninterruptible power supplies protect against power quality issues and outages. APC, Eaton, and Schneider Electric lead the industrial UPS market.
Surge Protection
SPDs protect sensitive electronics from voltage transients. Phoenix Contact, DEHN, and ABB offer comprehensive protection solutions for power and signal lines.
Making the Right Choice
Selecting automation equipment involves balancing multiple factors:
- Ecosystem compatibility: Staying within one vendor ecosystem simplifies integration and support
- Application requirements: Match equipment capabilities to actual needs—do not over-specify
- Total cost of ownership: Consider installation, programming, maintenance, and spare parts
- Support availability: Local technical support and parts availability matter for critical systems
- Future scalability: Choose platforms that can grow with your needs
Understanding these categories and the strengths of different manufacturers empowers you to design robust, cost-effective automation systems. Whether you are specifying a new installation or maintaining legacy equipment, this knowledge forms the foundation of successful industrial automation.