The plant needed a reliable conveyor control for material handling with safety interlocks.

Create a ladder logic that starts the motor on a push‑button, stops it on another button, and shuts down immediately on an emergency stop.

Programmed three rungs: (1) a start rung using a normally open start push‑button and a holding contact; (2) a stop rung with a normally closed stop button; (3) an emergency stop rung using a normally closed E‑Stop contact in series with the motor coil, ensuring it overrides all other inputs. Added status indicators and a fault latch for diagnostics.

The conveyor operated smoothly, met all safety standards, and the E‑Stop instantly cut power, eliminating previous near‑miss incidents.

A temperature regulation loop required precise control to maintain product quality.

Explain the control strategies and select the appropriate one for the application.

Described that an ON/OFF controller switches output fully on or off based on a setpoint threshold, leading to oscillation around the setpoint. A PID controller continuously adjusts output using proportional, integral, and derivative terms to minimize error, providing smooth and accurate control. Recommended ON/OFF for simple heating where precision isn’t critical, and PID for processes needing tight tolerance, such as temperature or speed control.

The team implemented a PID for the temperature loop, reducing variance from ±5 °C to ±0.2 °C, while using ON/OFF for a low‑cost fan control where precision was unnecessary.

The assembly line experienced intermittent motor stalls every 2–3 hours, causing production loss.

Identify root cause, implement a fix, and prevent recurrence without major downtime.

1. Collected fault logs and correlated stall times with temperature and load data. 2. Conducted a step‑by‑step isolation: inspected motor, drive, and sensor wiring. 3. Discovered that a loose terminal on the motor drive caused voltage drops under load. 4. Secured the connection, added a vibration‑resistant terminal block, and updated maintenance SOPs. 5. Monitored the line for a week to verify stability.

Stalls ceased completely; line uptime improved by 12%, saving approximately $45,000 per month. The new SOP reduced similar issues on other lines.

In Q3 FY, I was assigned three automation upgrades: a PLC retrofit, a HMI redesign, and a safety interlock audit, all due within the same month.

Create a prioritization plan that meets business goals and resource constraints.

1. Assessed each project's business impact, regulatory urgency, and resource requirements. 2. Scored projects using a weighted matrix (impact 40%, urgency 30%, effort 30%). 3. Communicated the ranking to stakeholders and secured additional resources for the high‑impact PLC retrofit. 4. Established a phased schedule, delivering the safety audit first (regulatory), followed by the PLC retrofit, and finally the HMI redesign.

All projects were completed on time; the safety audit avoided potential compliance fines, and the PLC upgrade increased line efficiency by 8%.

The production manager was hesitant to replace the legacy pneumatic system with a servo‑driven solution due to perceived cost and reliability concerns.

Demonstrate the value and reliability of the new technology to gain approval.

1. Conducted a cost‑benefit analysis highlighting reduced energy consumption and maintenance. 2. Arranged a pilot on a low‑risk cell and collected performance data. 3. Presented pilot results, showing a 25% cycle‑time reduction and 30% lower energy use. 4. Addressed concerns by outlining a phased rollout and training plan.

Stakeholder approved the rollout; the company saved $120,000 annually on energy and maintenance, and cycle time improved across the line.