How does a part reject module know that a part should be rejected?

How does a part reject module know that a part should be rejected?

• A. Vision system
• B. Operator input
• C. Mechanical switch
• D. PLC

Answer: (D)

The part reject decision is handled by the central control logic that coordinates sensing, decision-making, and actuation. A PLC serves as that central controller in many automation lines. It collects input signals from sensors (for example, a vision system that detects a defect) and runs the rejection criteria or rules. When the PLC determines a part is defective, it sends a precise control signal to the reject module to actuate the ejector at the exact right moment as the part passes by. This setup ensures reliable timing and synchronization across the line, so defective parts are removed consistently. A vision system by itself detects and identifies potential defects, but it usually hands off that information to the PLC, which applies the decision logic and triggers the ejector. Operator input is impractical for high-speed production because it’s slow and not feasible for automatic, continuous operation. A mechanical switch is just a simple sensor and lacks the sophistication to make defect decisions; it might indicate position or a fault but doesn’t provide the structured decision-making and timing needed to reject parts automatically.

The part reject decision is handled by the central control logic that coordinates sensing, decision-making, and actuation. A PLC serves as that central controller in many automation lines. It collects input signals from sensors (for example, a vision system that detects a defect) and runs the rejection criteria or rules. When the PLC determines a part is defective, it sends a precise control signal to the reject module to actuate the ejector at the exact right moment as the part passes by. This setup ensures reliable timing and synchronization across the line, so defective parts are removed consistently.

A vision system by itself detects and identifies potential defects, but it usually hands off that information to the PLC, which applies the decision logic and triggers the ejector. Operator input is impractical for high-speed production because it’s slow and not feasible for automatic, continuous operation. A mechanical switch is just a simple sensor and lacks the sophistication to make defect decisions; it might indicate position or a fault but doesn’t provide the structured decision-making and timing needed to reject parts automatically.