300+ Automation Engineer Interview Questions and Answers

Yes, I have knowledge of servo drives.

• I have experience in programming and troubleshooting servo drives.

• I am familiar with different types of servo drives such as AC and DC servo drives.

• I have worked with servo motors and have knowledge of their operation and control.

• I have experience in integrating servo drives with PLCs and other automation systems.

• I am familiar with industry standards and safety regulations related to servo drives.

Input and output are signals that are used to communicate between the PLC and external devices.

• Inputs are signals received by the PLC from sensors or other devices.

• Outputs are signals sent by the PLC to actuators or other devices.

• PLC processes the input signals and generates the output signals based on the program logic.

• Examples of inputs include switches, sensors, and analog signals.

• Examples of outputs include motors, valves, and alarms.

The maximum number of repeating characters in a string needs to be determined.

• Iterate through each character in the string and keep track of the count of consecutive repeating characters.

• Update the maximum count whenever a new maximum is found.

• Return the maximum count at the end of the iteration.

I used OOPS concepts in my framework for creating reusable components and maintaining code modularity.

• Used inheritance to create a base class with common functionalities shared by multiple classes

• Implemented polymorphism to allow different classes to implement the same method in their own way

• Encapsulated data and behavior within classes using access modifiers like private and public

• Utilized abstraction to hide the implementation details of certain classes from other parts of ...read more

Power factor is the ratio of real power to apparent power in an AC circuit.

• Power factor = Real power / Apparent power

• It is measured in a scale of 0 to 1 or 0 to 100%

• A power factor of 1 means all the power is being used efficiently

• A power factor of less than 1 means some power is being wasted

• Capacitors can be used to improve power factor

The output will be 'HelloThere'

• Concatenation of 'Hello' and 'There' results in 'HelloThere'

• The final string is printed using System.out.println()

To find the 2nd maximum salary from the employee table

• Order the salaries in descending order

• Use LIMIT 1,1 to get the second highest salary

IEC61850 offers advanced features and benefits over Modbus.

• IEC61850 offers faster communication speed and higher data capacity than Modbus.

• IEC61850 is designed for complex substation automation systems, while Modbus is more suitable for simple applications.

• IEC61850 offers standardized data models and object-oriented programming, making it easier to integrate with other systems.

• IEC61850 supports peer-to-peer communication, while Modbus requires a master-slave architecture.

• IEC6...read more

I have programming experience in various languages including Java, Python, and C++.

• Proficient in Java, Python, and C++

• Experience with automation frameworks such as Selenium and Appium

• Familiarity with Agile methodology and version control systems like Git

• Developed test scripts for web and mobile applications

• Implemented automation solutions for regression testing and continuous integration

• Participated in code reviews and collaborated with cross-functional teams

Wrapper classes are classes that allow primitive data types to be used as objects.

• Wrapper classes provide a way to use primitive data types as objects in Java.

• They are used for typecasting and to perform various operations on primitive data types.

• Examples of wrapper classes include Integer, Float, Boolean, etc.

• Wrapper classes are commonly used in automation testing with tools like Selenium.

Check page load completion using browser tools and wait for specific elements

• Use browser developer tools to check network activity and resource loading

• Wait for specific elements or events to be present on the page

• Utilize JavaScript functions like document.readyState or jQuery's document.ready

Classes can have both implementation and state, while interfaces only have method signatures.

• Classes can have constructors, interfaces cannot

• Classes can have fields, interfaces cannot

• A class can implement multiple interfaces, but can only inherit from one class

• Example: Class 'Car' can have fields like 'color' and 'model', while Interface 'Drivable' only has method signatures like 'start' and 'stop'

Extract pincode from a given address string.

• Split the address string by spaces to get individual words

• Check each word to see if it is a valid pincode (numeric and 6 digits)

• Return the first valid pincode found

I use Selenium WebDriver to write automation test scripts.

• Selenium WebDriver is a popular tool for automating web applications

• It supports multiple programming languages like Java, Python, C#

• Allows interaction with web elements like buttons, text fields, etc.

• Can perform actions like click, type, select, etc. on web elements

Mechanical components like pneumatics and motors work by converting energy into mechanical motion to perform specific tasks.

• Pneumatics use compressed air to create motion, often used in industrial automation for tasks like gripping and lifting.

• Motors convert electrical energy into mechanical motion, commonly used in automation for driving conveyor belts or robotic arms.

• Pneumatic cylinders use air pressure to move a piston, which in turn moves the connected machinery.

• Motors ca...read more

VFD stands for Variable Frequency Drive, a type of motor controller that drives an electric motor by varying the frequency and voltage supplied to the motor.

• VFDs are used to control the speed and torque of AC induction motors by varying the frequency of the electrical input.

• They are commonly used in industrial applications to save energy, improve process control, and reduce wear and tear on equipment.

• VFDs can be programmed to operate in different modes such as speed control, ...read more

OPC communication is a standard protocol used for data exchange between different industrial automation systems.

• OPC stands for OLE (Object Linking and Embedding) for Process Control

• It allows communication between devices from different manufacturers

• OPC servers provide data to OPC clients using a common language

• OPC UA (Unified Architecture) is the latest version of OPC with improved security and scalability

Yes, I have experience in SCADA.

• I have worked with various SCADA systems such as Wonderware, Ignition, and Inductive Automation.

• I have experience in designing and implementing SCADA systems for industrial automation.

• I am familiar with programming languages such as ladder logic, structured text, and function block diagram used in SCADA systems.

• I have experience in troubleshooting and maintaining SCADA systems to ensure optimal performance.

XPSTH is a query language for XML documents, Epic in Jira is a user story or task, 204 status code means successful response with no content.

• XPSTH is a query language used to navigate through XML documents.

• Epic in Jira refers to a large user story or task that can be broken down into smaller stories or tasks.

• 204 status code indicates a successful response from the server with no content to return.

Use Selenium WebDriver to find all web elements in a web page

• Instantiate a WebDriver object using Selenium

• Use findElements method to locate all elements on the page

• Store the found elements in a list for further processing

SQL joins are used to combine data from two or more tables based on a related column.

• Inner join returns only the matching rows from both tables

• Left outer join returns all rows from the left table and matching rows from the right table

• Right outer join returns all rows from the right table and matching rows from the left table

• Full outer join returns all rows from both tables, with NULL values in non-matching rows

In automation testing, we test the functionality, performance, and security of software applications.

• We test the functionality of the software to ensure that it meets the requirements and specifications.

• We test the performance of the software to ensure that it can handle the expected load and response times.

• We test the security of the software to ensure that it is protected against potential threats and vulnerabilities.

• We also test the compatibility of the software with diffe...read more

I have worked with various types of PLCs including Siemens, Allen Bradley, and Mitsubishi.

• Siemens PLCs are commonly used in industrial automation and have a user-friendly programming interface.

• Allen Bradley PLCs are known for their reliability and are widely used in manufacturing processes.

• Mitsubishi PLCs are popular in the automotive industry and offer advanced motion control capabilities.

Yes, I have written static methods in my previous projects.

• Yes, I have written static methods for utility functions that do not require an instance of the class to be created.

• Static methods are commonly used for helper functions, mathematical calculations, or any operation that does not depend on the state of the object.

• For example, a static method to convert temperature units or calculate the area of a circle.

Rockwell Software used names for their software products instead of version numbers.

• Rockwell Software used names like RSLogix, FactoryTalk, and Studio 5000 for their software products.

• This naming convention made it easier for customers to identify and differentiate between different software products.

• The names also helped to create brand recognition and loyalty among customers.

• Rockwell Software continues to use this naming convention for their software products today.

Real time graphs show current data while historical graphs show past data.

• Real time graphs display data as it is happening, while historical graphs show data from a specific time period.

• Real time graphs are useful for monitoring current trends and making immediate decisions, while historical graphs are useful for analyzing past trends and making long-term decisions.

• Examples of real time graphs include stock market tickers and weather radars, while examples of historical graph...read more

The code creates a StringBuffer object with 'Hello' and appends 'There' to it before printing the final string.

• StringBuffer is mutable, so the original 'Hello' string can be modified

• The append() method adds the specified string to the end of the buffer

• The final output will be 'HelloThere'

Handling multiple tabs in Selenium involves switching between tabs and performing actions on each tab.

• Use getWindowHandles() to get a set of window handles

• Switch to a specific tab using switchTo().window(handle)

• Perform actions on the tab

• Close the tab if needed using driver.close()

Code to find implicit and explicit wait in automation testing

• For implicit wait, set a global timeout for the driver to wait for elements to be available before throwing an error

• Example: driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);

• For explicit wait, wait for a specific condition to be met before proceeding with the test

• Example: WebDriverWait wait = new WebDriverWait(driver, 10); wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("elementId")));

PLCs are specialized computers used for industrial automation, while microcontrollers are small computers used in various electronic devices.

• PLCs are designed for controlling industrial processes, while microcontrollers are used in a wide range of electronic devices.

• PLCs are typically programmed using ladder logic or other specialized languages, while microcontrollers are programmed using C/C++ or other high-level languages.

• PLCs are more robust and reliable for industrial app...read more

Automation is the use of technology to perform tasks without human intervention.

• Increases efficiency and productivity

• Reduces errors and improves accuracy

• Saves time and money

• Allows for 24/7 operation

• Enables scalability and consistency

• Examples include robotic process automation, industrial automation, and test automation

I chose testing domain because of my interest in ensuring quality and reliability of software products.

• I enjoy finding and fixing bugs in software

• I believe in the importance of delivering high-quality products to customers

• I have a strong attention to detail and enjoy the process of testing

• I find it satisfying to ensure that software meets the requirements and specifications

• I have experience in testing and enjoy the challenge of finding new ways to improve the testing process

Java code to print frequency of each character in a string

• Create a HashMap to store character frequencies

• Iterate through the string and update the frequencies in the HashMap

• Print the frequencies of each character

RS485 is a differential serial communication standard that allows multiple devices to communicate on the same bus, while RS232 is a single-ended serial communication standard for point-to-point communication.

• RS485 is a differential standard, allowing for longer cable lengths and higher data rates compared to RS232.

• RS485 supports multi-point communication, allowing multiple devices to communicate on the same bus, while RS232 is typically used for point-to-point communication.

• R...read more

The main automation tools include Selenium, Appium, UFT, TestComplete, and Robot Framework.

• Selenium is a popular open-source tool for web application testing

• Appium is used for mobile application testing

• UFT (formerly QTP) is a commercial tool for functional testing

• TestComplete is a commercial tool for automated UI testing

• Robot Framework is a generic open-source automation framework

STP stands for Spanning Tree Protocol. It is a network protocol that ensures a loop-free topology in Ethernet networks.

• STP is used to prevent loops in Ethernet networks by blocking redundant paths.

• It works by electing a root bridge and calculating the shortest path to it for each network segment.

• STP uses Bridge Protocol Data Units (BPDUs) to exchange information between switches.

• If a link or switch fails, STP recalculates the topology to maintain network connectivity.

• STP has ...read more

VFD stands for Variable Frequency Drive.

• It is an electronic device that controls the speed of an AC motor by varying the frequency of the electrical supply to the motor.

• It is used to save energy and improve process control in industrial applications.

• VFDs are commonly used in HVAC systems, pumps, fans, and conveyors.

• They can also be used to control the speed of electric vehicles and wind turbines.

Computer Numerical Control

• CNC stands for Computer Numerical Control

• It is a manufacturing process where pre-programmed computer software dictates the movement of factory tools and machinery

• CNC machines are used in various industries such as automotive, aerospace, and electronics

• Examples of CNC machines include CNC mills, lathes, and routers

Active components require a power source to operate and can control the flow of electricity, while passive components do not require a power source and cannot control the flow of electricity.

• Active components require a power source to function, such as transistors, diodes, and integrated circuits.

• Passive components do not require a power source and include resistors, capacitors, and inductors.

• Active components can amplify signals, while passive components cannot.

• Active compon...read more

Yes, I have experience with SCADA systems in previous roles.

• Implemented SCADA systems to monitor and control industrial processes

• Configured alarms and notifications for abnormal conditions

• Analyzed data trends to optimize system performance

• Integrated SCADA with PLCs for seamless automation

• Troubleshooted and resolved issues with SCADA systems

Yes, I have experience using Rockwell PLC in previous projects.

• I have used Rockwell PLC in previous projects for automation tasks

• I am familiar with programming languages such as ladder logic and structured text for Rockwell PLC

• I have experience troubleshooting and debugging Rockwell PLC systems

Writing code for test automation using tools like Selenium with Java or Cypress with JavaScript.

• Choose the tool+language combination based on project requirements and team expertise.

• Write maintainable and scalable code for test automation scripts.

• Utilize best practices and design patterns for efficient automation code.

• Regularly update code to adapt to changes in the application under test.

• Leverage frameworks like TestNG or Mocha for better test organization and reporting.

Yes, I have worked in Codesys platform.

• I have experience in developing PLC programs using Codesys.

• I have worked with Codesys version 2.3 and 3.5.

• I am familiar with programming languages such as Structured Text, Function Block Diagram, and Ladder Diagram in Codesys.

• I have developed programs for various industrial automation applications such as conveyor systems, packaging machines, and robotic arms using Codesys.

Distributed PLC architecture allows for multiple PLCs to communicate with each other while centralized PLC architecture has a single PLC controlling all processes.

• Distributed PLC architecture is more flexible and scalable

• Centralized PLC architecture is simpler and easier to maintain

• Distributed PLC architecture is better suited for large and complex systems

• Centralized PLC architecture is better suited for smaller systems with fewer processes

• Examples of distributed PLC architec...read more

Answer to Jova codes to reverse strings and remove duplicate in array

• To reverse a string, use the reverse() method or loop through the string in reverse order

• To remove duplicates in an array, use the Set() method or loop through the array and use a temporary object to store unique values

Programming languages vary in types and details, each with unique features and use cases.

• There are different types of programming languages such as procedural, object-oriented, and functional.

• Examples of popular programming languages include Java, Python, C++, and JavaScript.

• Each programming language has its own syntax, rules, and best practices for coding.

• Some languages are better suited for specific tasks like web development, data analysis, or system programming.

bashrc and .profile are configuration files for the Bash shell in Linux/Unix systems.

• bashrc is executed for every new interactive shell session

• .profile is executed only once during login

• They contain environment variables, aliases, and other shell settings

• bashrc is typically used for user-specific settings, while .profile is system-wide

• Examples: setting PATH variable, defining aliases, setting prompt