How is a robotic cell commonly integrated with a PLC, and what information is typically exchanged?

• A. Robot controls PLC
• B. PLC handles I/O, sequencing, safety interlocks; the robot reports status, error codes, and I/O signals; use fieldbus or Ethernet/IP/PROFINET.
• C. No data exchange is performed
• D. PLC is replaced by the robot controller

Answer: (B)

In a typical robotic cell, the PLC acts as the central control core for the line, handling input/output decisions, sequencing of tasks, and safety interlocks. The robot controller focuses on executing motion and task steps. They communicate in a two-way data exchange: the PLC sends start/stop commands, enables I/O operations (like gripping, ejecting, or conveyor control), and enforces safety actions; the robot reports its status, error codes, and actual I/O states back to the PLC. This information flow often travels over industrial networks such as fieldbus, or Ethernet-based protocols like EtherNet/IP or PROFINET, ensuring fast and deterministic communication between devices. The combined setup lets the PLC coordinate the overall process and safety with the robot’s precise motion, while the robot provides real-time feedback to keep the cell synchronized.