Most Asked Industrial Automation Interview Questions
Tags: engineering, automation
Published: 2023-08-03 14:46:55

Here are sample answers to some advanced industrial automation interview questions:

## Are you comfortable working with complex systems?

Yes, I have experience working with complex industrial automation systems that involve multiple hardware and software components. I approach complex problems systematically, breaking them down into smaller, more manageable issues. 

I also leverage resources like documentation, online forums, and colleagues to help solve complex issues. Through troubleshooting complex systems, my problem-solving and critical thinking skills have improved.

## How would you go about troubleshooting a system that's not working properly?

I would start by gathering as much information as possible - error messages, logs, feedback from operators. I would then form a hypothesis of potential issues based on my knowledge and experience. I would systematically test components, starting with the easiest and working my way up. I would isolate each component to determine if it is functioning properly. 

I would leverage resources like documentation, online forums, and colleagues for assistance. If necessary, I would rebuild components from scratch to rule out software or configuration issues. Through this process, I would identify the root cause and develop a solution.

## What is a PLC, and how would you use one in your work as an automation engineer?

A **[PLC (Programmable Logic Controller) system implementation service ](https://ipacautomation.com/service/plc-dcs-system-implementation-services/)**is a specialized industrial computer used to control machinery and processes. As an automation engineer, I would use PLCs to implement the control logic for automated systems. 

I would program the PLC using ladder logic or function block diagrams to define the input, output, and logic functions. The PLC would then monitor sensors and switch actuators based on my defined control logic. This allows me to automate complex processes that previously required human intervention.

## Provide an example of a time when you had to use your engineering skills to solve a problem.

One example is when I had to troubleshoot an issue with an automated bottling line. The line was experiencing intermittent jamming in the capper section. I reviewed the PLC logic and wiring diagrams but found no obvious issues. 

I then observed the line in operation and noticed that the jamming occurred when two bottles passed closely together. This indicated a timing issue. I adjusted the cycle time of the capper slightly and was able to eliminate the jamming without affecting overall throughput. 

By thinking through the problem systematically and observing the real-world behavior, I was able to identify and implement an effective solution.

**Here are some common technical control engineering interview questions:
**

## 1. Can you explain the difference between open-loop and closed-loop control systems?

Open-loop systems have the output determined solely by the input, without any feedback. They are simple but prone to inaccuracies. 

Closed-loop systems incorporate feedback from the output to adjust the input and minimize errors. They provide greater accuracy but are more complex.

## 2. What is a PID controller, and how do you tune its parameters?

**[A PID controller](https://www.omega.co.uk/prodinfo/pid-controllers.html)** stands for Proportional-Integral-Derivative. It adjusts the output based on the P, I, and D gains.

Tuning involves finding optimal values for the gains:

- Increase P gain until oscillations occur, then increase I gain to eliminate steady state error
- Ziegler-Nichols method provides guidelines for initial gains
- Software optimization techniques iteratively adjust parameters to optimize performance

## 3. Describe your experience with PLC programming languages.

The interviewer wants to gauge your proficiency with languages like Ladder Logic and Structured Text. You can discuss relevant projects where you programmed PLCs and collaborated with other teams.

## 4. How do you design a control system to minimize overshoot and settling time?

You can discuss:

- Choosing a PID controller and tuning the gains
- Adjusting the integral gain to reduce settling time while avoiding overshoot
- Incorporating feedforward or advanced control techniques

## 5. What are some common types of sensors used in control engineering?

Temperature sensors (thermocouples, RTDs), pressure sensors (piezoelectric, strain gauge), and flow sensors (ultrasonic, electromagnetic) are widely used.

## 6. Explain the concept of feedback in control systems.

Feedback uses a portion of the output signal to influence the input signal. It stabilizes the system by counteracting deviations and minimizing errors. Negative feedback is more common.

## 7. Can you explain the concept of Programmable Logic Controllers (PLCs) and their significance in industrial automation?

PLCs are specialized digital computers used in industrial automation to control various processes and machinery. They are essential as they provide real-time control, flexibility, and reliability in automating complex tasks.

PLCs can handle multiple inputs and outputs, execute logic and arithmetic operations, and communicate with other devices, making them a crucial component in modern industrial automation systems.

## 8. Describe your experience in designing and implementing Human-Machine Interfaces (HMIs) for industrial control systems.

I have extensive experience in designing intuitive HMIs that facilitate seamless interaction between operators and industrial systems. I prioritize user-friendly interfaces with clear visualizations of real-time data, such as process parameters, alarms, and trends.

Also, I ensure that the HMI design adheres to industry standards and best practices to enhance overall system efficiency and reduce operator errors.

## 9. How do you approach troubleshooting and resolving complex automation system issues?

Sample Answer: Troubleshooting complex automation issues requires a systematic approach. Firstly, I gather as much data and information as possible about the problem's symptoms and root cause. 

Then, I use various diagnostic tools and software to analyze PLC logs, communication protocols, and sensor readings. If necessary, I perform simulated tests to replicate the problem in a controlled environment. Once I identify the issue, I collaborate with relevant teams to devise and implement an effective solution, while ensuring minimal disruption to production.

## 10. How do you stay up-to-date with the latest advancements in industrial automation technologies?

To stay current in the rapidly evolving field of industrial automation, I regularly attend industry conferences, webinars, and workshops. I also follow reputable online platforms, subscribe to industry-specific publications, and participate in automation-related forums. 

Moreover, I actively engage with colleagues and experts in the automation community to exchange knowledge and insights.