Top 15 Always Asked SCADA Interview Questions

Are you a fresher and searching for a job in the field of Automation, Instrumentation, Electrical? Then this article might be helpful for you to crack some of the interview questions related to SCADA.

We are listing here some of the most popular and most asked SCADA interview questions based on our working experience in the field of Instrumentation.

No matter what if you are a fresher or experienced, this list will help you to add more value to your SCADA knowledge.

So further not waste more time and Let’s explore the list.


Most Important SCADA Interview Questions-Answers

Here is the list of most important SCADA interview questions-answers, which are often asked in interviews.

1) What is SCADA?

SCADA is the short abbreviation of Supervisory Control and Data Acquisition. SCADA generally refers to an industrial computer system that monitors and controls a process.

SCADA mainly does three operations:

  • Supervise real-time data in the form of graphical presentation
  • Control industrial processes locally or through Remote locations
  • Acquire real-time data as well as logs data

Read the complete tutorial about What is SCADA?


2) What are the differences between PLC and SCADA?

The main difference between PLC(Programmable Logic Controller) and SCADA(Supervisory Control and Data Acquisition) is that PLC is a hardware part while SCADA is a software part.

PLC is designed to control the complex process of a plant through a user program and fully scalable as per the operator’s requirement.

SCADA is generally used to monitor and control the machines. It is typically software that is installed on a computer. SCADA is used in combination with PLC and other controllers.


3) Features of SCADA?

There are very important features which SCADA provides and very useful to control a running process like,

  • Control feature using a graphical representation
  • Real and Historical Trends
  • Alarm Handling
  • Recipe Management
  • Report Generation
  • Security Management

Read the complete tutorial about Features of SCADA?


4) Leading SCADA providers companies.

The most popular SCADA brands ⇒

  • Siemens WinCC
  • Wonderware Intouch
  • Allen Bradley RSView
  • Ge Fanuc Simplicity

5) What is HMI?

HMI (Human Machine Interface) is a device or software that is used to communicate with the machines or groups of machines in the plant or production area.

HMI directly connect the human with the machine just by translating the huge amount of complex data into accessible information via graphical representation on the monitor.

Read a complete tutorial about What is HMI?


6) What is RTU?

RTU stands for the Remote Terminal Unit, which is generally a microprocessor-based device that directly connects the field sensors with the plant control or SCADA.


7) What is DDE?

DDE stands for the Dynamic Data Exchange. This is the communication protocol that provides a facility to send and receive data between different devices. This communication protocol is generally developed by Microsoft.


8) Difference between SCADA and HMI.

HMI(Human Machine Interface) on SCADA(Supervisory Control and Data Acquisition), can also monitor and control anything that is connected to the same network. Thus HMI can be a part of SCADA but SCADA can’t be a part of HMI.


9) What are the trends in SCADA?

Trends are essential for any industrial automation system.

SCADA system is capable to store the real-time data from fields, retrieve historical data, and present them in a graphical manner.

There are two types of trends are available in the SCADA system :

  • Real-Time Trend ⇒ Real-Time trends are continuously updated within the span time given in the configuration.
  • Historical Trend ⇒ Historical trends are the trends that the user can configure to update for the selected time span given by the user. Users can zoom in and zoom out the trends, also take a screenshot and print.

SCADA Software


10) What are Alarms?

An alarm system is a system designed to direct the attention of the operator to significant aspects of the current state of the plant. SCADA can perform this task with high accuracy.

It can track deviation in the rate of change monitoring for analog values as well as a change in the digital input/output values. It can display historical alarm also.

SCADA Software


11) Explain about Security Management in SCADA.

Security Management is a facility in the SCADA system that provides functionality to decide specific function can operate by the specific user only.

Security is provided by the login, User name and Password is given to the specific persons. Users can create a specific group like

  • Admin
  • Operator
  • Maintenance In-charge

SCADA interview questions


12) Explain the Report function of SCADA.

SCADA provides an amazing functionality – Report. The user has to prepare a format in which they want a report. The user can select an event that triggers a report. There is also functionality that a user can generate a report manually at any time.

SCADA Software


13) What is the use of Scripts in SCADA?

Scripts are basically a function that reduces the user effort of doing the same operation in a repeated manner.

Users can create their own scripts in SCADA and store it. The SCADA provides a C, VBS, etc. language support to write down scripts.

Some typical examples of scripts are as below ⇒

  • Historical Trends
  • Start and Stop functionality of Group of Machines
  • Timer
  • Real-time Date and Month showing
  • Report Generation in Excel by User has given SPAN time
  • Auto Report Generation at a specific time in a day

14) What is Licensing in SCADA software?

You must have a valid license to use the SCADA software. There are mainly two types of license patterns are available in the SCADA software.

Hardware Lock Hardware lock is installed on one of the ports of the hardware like USB, communication port, etc.

Software Lock Software lock is the code you have provided while purchasing a SCADA software which you have to enter while installing software on the PC.


15) What is CIMPLICITY?

CIMPLICITY is a SCADA package, it is based on a client-server architecture consisting of server and viewers. Data collection and distribution is the responsibility of servers.


This is the list of most asked SCADA interview questions in the interview of Instrumentation Engineering students and even Automation professionals.

I hope this list of SCADA interview questions will help you. If you have any queries then please feel free to comment down below.


You can also find the books to boost your knowledge in Instrumentation, PLC, SCADA by clicking below link ⇒

Instrumentation and Control related books

PLC related books

SCADA related books


If you like this blog then please share this blog with your friends and colleagues. Each comment matters for us and gives us the motivation to share more and more knowledge with you all!

Share this blog,

Leave a Comment