Industrial robots are increasingly common in UK manufacturing, from automotive assembly to food packaging. However, a robot operating in isolation provides limited value. The real productivity gains come from integrating robots with PLC-based automation systems, conveyors, safety systems, and quality inspection equipment.
Robot-PLC Communication Methods
Digital I/O (handshaking): The simplest integration method uses discrete digital signals between the robot controller and PLC. Signals include robot ready, cycle start, cycle complete, fault, and zone safety. This method is suitable for simple pick-and-place applications.
Fieldbus communication (PROFINET, EtherNet/IP): Modern robot controllers support industrial Ethernet protocols that enable rich data exchange. The PLC can send part numbers, position offsets, programme selection commands, and receive robot status, position data, and diagnostic information.
Shared memory or direct connection: Some robot brands (including KUKA with mxAutomation and Fanuc with ROBOGUIDE) allow the PLC to directly control robot motion, effectively making the robot an extension of the PLC programme.
Designing a Robotic Workcell
A well-designed robotic workcell considers:
Mechanical layout:
- Robot reach envelope and payload capacity
- Part presentation and fixturing
- Material flow in and out of the cell
Safety system:
- Physical guarding with interlocked access doors
- Safety-rated sensors (light curtains, safety mats, area scanners)
- Safe speed monitoring and collaborative operation zones (where applicable)
- Risk assessment per ISO 10218 and ISO/TS 15066
Control architecture:
- The PLC serves as the cell controller, coordinating robot actions with conveyors, fixtures, and quality systems
- The robot controller handles motion planning and tool control
- The HMI provides operator interface for mode selection, recipe management, and diagnostics
Common Integration Patterns
Sequential operation: The PLC controls the overall process sequence. When a part is in position and conditions are met, the PLC signals the robot to execute a predefined programme. The robot signals completion, and the PLC advances to the next step.
Coordinated motion: The robot and external axes (conveyors, turntables) operate simultaneously. The PLC manages synchronisation to ensure the robot picks or places parts while the conveyor is moving.
Flexible manufacturing: The PLC selects different robot programmes based on product type, received from a barcode reader or MES system. This enables mixed-model production on the same line.
Collaborative Robots (Cobots)
Collaborative robots are increasingly popular for applications where humans and robots work in close proximity:
- Force and speed limiting enables operation without traditional guarding
- Easier programming through teach pendants and hand guiding
- Flexible deployment with quick changeover between tasks
- Risk assessment is still mandatory, even for cobots
Career Opportunities
Engineers with combined PLC and robotics skills are highly sought after in the UK market. Roles include robotic cell programmer, automation project engineer, and robotics system integrator, with salaries typically ranging from GBP 40,000 to GBP 70,000.
Robotics Integration at EDWartens UK
EDWartens UK offers robotics integration training that covers PLC-robot communication, safety system design, and workcell commissioning. Our courses combine virtual simulation with real hardware to provide comprehensive practical experience.