Tell us about a time when you had to troubleshoot a control system issue. How did you identify and resolve the problem?

One time, I encountered a control system issue at a manufacturing facility where the machine was not operating as expected. To identify the problem, I first reviewed the system logs and checked the error codes on the HMI panel. I also examined the PLC program to ensure all the logic was correct. After further investigation, I discovered that a sensor was faulty, which was causing incorrect feedback to the control system. To resolve the issue, I replaced the faulty sensor and recalibrated it to ensure accuracy. Finally, I tested the system to ensure it was functioning properly and documented the troubleshooting process for future reference.

During my time as a control systems engineer at an automotive plant, there was a critical issue with the production line. The motors controlling the conveyor belts were not responding properly, causing disruptions in the assembly process. To identify the problem, I conducted a thorough analysis of the motor control system, including reviewing the PLC code, examining the wiring connections, and conducting sensor calibration. Through this process, I discovered that the issue was caused by a faulty motor drive. To resolve the problem, I replaced the faulty drive with a new one and reprogrammed it to ensure compatibility with the existing control system. After implementing the solution, I conducted extensive testing to ensure the motors were functioning correctly and the production line was back to full operation. This experience highlighted the importance of attention to detail and the ability to quickly diagnose and resolve complex control system issues.

In my role as a control systems engineer at a chemical processing plant, I encountered a control system issue that had a significant impact on production. The system responsible for maintaining the temperature and pressure in a reactor vessel was malfunctioning, leading to unstable process conditions. To address this problem, I took a systematic approach. First, I reviewed the system documentation and previous maintenance reports to understand the history of the control system. Then, I conducted a comprehensive analysis of the system's instrumentation, including checking sensor accuracy, inspecting wiring connections, and verifying calibration. After a thorough examination, I realized that the issue was not with the control system itself, but with the underlying process dynamics. I worked closely with process engineers to model and simulate the reactor's behavior, allowing us to identify the root cause of the instability. Based on this analysis, I proposed several modifications to the control algorithm, including adjusting the PID parameters and implementing advanced control strategies. I collaborated with a team of technicians to implement the changes, carefully monitoring the system's response and fine-tuning the settings as needed. The result was a significant improvement in process stability and a reduction in off-spec products. This experience showcased my ability to troubleshoot complex control system issues by combining analytical skills, deep technical knowledge, and collaboration with cross-functional teams.