Conveyor Control with Siemens LOGO PLC

Goal:
To design an automated conveyor system that detects objects on the belt and responds without operator action, and to learn how PLCs combine sensor inputs, timing and motor control in real industrial processes.

What I built:
A working conveyor driven by an electric motor and controlled by a Siemens LOGO PLC. Industrial proximity sensors detect each item as it arrives: an inductive proximity sensor senses metal objects, and a capacitive sensor senses non-metal objects such as plastic, wood or cardboard. The PLC program stops the belt, holds it for a set time and restarts it automatically, and counts the items that pass. Start, stop and emergency stop push buttons on the control panel give the operator manual control, and indicator lamps show whether the system is running, stopped or in an emergency stop.

My role:
Working with my project team at DUET, I designed the control circuit, wired the PLC, sensors, motor and operator controls, wrote and tested the LOGO PLC program, and adjusted the sensors' positions, sensing distances and timing until the system ran reliably.

Challenges / results:
The main challenges were setting each sensor's sensing distance so it detected objects consistently without false triggers, and writing a program that handled the start, stop, hold, restart and counting sequence correctly. The emergency stop had to override every other state and stop the belt immediately. The finished conveyor detected and counted objects reliably and ran its full sequence automatically, showing how a compact PLC can run a complete automated process from a few simple inputs and outputs.

What came after:
The project built on my star-delta starter work and strengthened my PLC programming skills, leading on to my variable speed motor control project with a variable frequency drive. Together, these projects gave me a practical foundation in the industrial automation found throughout manufacturing and power plants.