What is Human Machine Interface


What is Human Machine Interface & What is SCADA & Difference between HMI and PLC & SCADA

A Human-Machine Interface (HMI) is a dashboard or user interface that establishes a connection between a person and a system, machine, layout or device. Although the term can be applied to any display that activates user interaction with a device, HMIs are primarily used in industrial settings. Even though Human Machine Interfaces (HMIs) may bear some resemblance to GUIs (Graphical User Interfaces), it is important to note that they are distinct entities. In fact, GUIs are frequently integrated into HMIs to enhance the visualization aspect of the interface. In industrial processes, HMIs serve various functions such as tracking production time tags and trends, visually screening data, monitoring machine inputs & outputs and overseeing KPIs. These interfaces are comparable to how one would interact with their air-conditioning system to check and control the temperature in their house. For example, a plant-floor operator may set an HMI to monitor the temperature of an industrial water cistern or determine if a specific pump is presently running, for details see & download What is Human Machine Interface?

Basic examples of HMIs include built-in screens on machines, tablets, and computer monitors. Regardless of their format or the terminology used, their objective is to provide insights into mechanical performance and progress. HMI technology is widely embraced by nearly all types of industrial organizations, along with a diverse array of other companies, to effectively engage with their machinery and enhance the efficiency of their industrial operations. Various industries, including Energy, Oil and gas, Food and beverage, Power, Manufacturing, Transportation, Recycling, Water and waste water, and many more, make use of HMIs. The individuals who commonly interact with HMIs are system integrators, operators, and engineers (specially control system engineers). These professionals rely on HMIs as essential resources to review and monitor processes, visualize data, and diagnose problems.


Difference between HMI and PLC?

+The HMI is specifically created for operator interface, while the Programmable Logic Controller PLC is created for industrial automation and control.

+The HMI utilizes touch screens, graphics, and keypads to interact with users, while the PLC applies function block diagrams, ladder logic, or structured text for programming.

+The HMI is used for monitoring and controlling process variables, while the PLC is capable of handling high-speed inputs and outputs.

+The HMI displays real-time process data and provides alarms and alerts, while the PLC can be programmed to execute complex control algorithms.

+The HMI communicates with the PLC and other devices through industrial protocols or OPC, while the PLC communicates using industrial protocols like Profinet, Modbus, and Ethernet/IP.

+Examples of HMI: Siemens Simatic HMI, Allen-Bradley PanelView, Pro-face GP4000 Series. Examples of PLC: Siemens, Allen-Bradley, Mitsubishi Electric.

+HMI, when used alongside PLC, is utilized to offer a user-friendly interface for monitoring and controlling industrial processes. PLC finds application in various industries, including process control, manufacturing, and building automation.

+HMI is responsible for displaying real-time process data and making necessary adjustments. PLC is programmed to execute complex control algorithms like PID control and motion control.

+HMI allows historical data logging and reporting, while PLC can be configured for remote access and monitoring.

+HMI supports multiple languages for easy operation by operators from different countries, while PLC integrates with other industrial devices such as sensors and actuators.

+HMI is primarily used for accessing data from the safety logic, while PLC is employed for safety applications such as emergency stop and interlocking.

+HMI is typically designed for indoor use in controlled environments, while PLC is capable of withstanding harsh industrial environments with wide temperature ranges, dust exposure, and vibration.

+HMI can be integrated with PLC and SCADA systems for monitoring purposes, while PLC can be used in stand-alone or networked configurations.

+HMI can be configured with user access levels and security measures to prevent unauthorized access or changes to the process. PLC program can be password protected to restrict unauthorized access.

+HMI allows for recipe management, making it easy for operators to switch between different process settings, while PLC allows for manual or automatic control of the process.

+HMI can be configured to provide real-time notifications through SMS, email, or other messaging systems, while PLC can integrate with IT systems like MES, ERP, and cloud-based platforms.

What is the use of HMI & What is Human Machine Interface?

HMI is mainly used to facilitate communication between input/output sensors, PLCs, and users by providing a platform to display relevant information. These displays can serve various functions, such as monitoring, control, and automation. Depending on their implementation, HMIs can perform simple tasks like tracking or more complex operations like adjusting production speed or shutting down machines. The primary goal of using HMIs is to optimize industrial processes by digitizing and centralizing data for easy access and analysis. By utilizing an HMI, operators can conveniently view critical information through charts, graphs, or digital dashboards, manage alarms, and connect with other systems like ERP, SCADA, and MES, all from a single console. In the past, operators had to physically inspect the production floor and manually record progress on paper or whiteboards. However, with HMI technology, PLCs can transmit real-time data directly to the HMI display, eliminating the need for this outdated practice and greatly reducing costly problems that arise from inadequate information or human error.

What is the meaning of HMI?

The term HMI means Human Machine Interface, refers to the essential tool utilized by operators and line supervisors in a plant or factory to coordinate and manage industrial and manufacturing processes. Essentially, an HMI serves as a dashboard or screen through which machinery can be controlled. In the industry, managers, line operators, and supervisors heavily rely on HMIs to convert intricate data into valuable information. These HMIs are used to monitor machinery, ensuring that they are functioning correctly. Through easily comprehensible visual displays, HMIs provide meaning and context to real-time information about variables such as tank levels, pressure and vibration measurements, motor and valve status, and more. Nevertheless, the advanced capabilities of modern HMIs enable managers and supervisors to go beyond process control. By utilizing historical and trending data, HMIs present extensive opportunities to enhance product quality and increase system efficiency. Due to all these reasons, HMIs play a pivotal role in ensuring the smooth and effective operation of factories and manufacturing processes.

What is HMI SCADA/What is Human Machine Interface

HMI/SCADA refers to a type of control system architecture that utilizes software and networked data to provide operators with a user-friendly interface. This interface allows them to monitor the performance of various equipment and issue commands and settings. This monitoring can be done from a dedicated screen, mobile device, or any PC connected to the control network through a web browser. Modern HMI/SCADA systems, along with data historian and centralized visualization technologies, empower users to fully utilize the potential of their data. The result is a highly productive development and visualization environment that optimizes plant operations. This is supported by faster development processes, the democratization of tools and capabilities throughout the plant, improved operational performance, reduced costs, a shift in employee mindset, and a culture of continuous improvement.

The use of HMI/SCADA enables operators to enhance situational awareness, access visualizations from anywhere, and control important equipment, all from a centralized view of operations. HMI/SCADA systems collect data from different control devices like RTUs, PLCs, flow meters, and temperature controllers. This data is then presented to operators through a Human Machine Interface (HMI). The HMI provides a real-time view of what is happening in the plant, including customized displays, alarms, trends, and more. This allows operators to make informed decisions and adjust machine controls or settings as needed. HMI/SCADA can also be integrated with other technologies, such as a data historian, to enable historical trending and analysis. The process starts with capturing industrial data and combining it with other relevant data sources to provide context and create a historical record. It is this data, transformed into meaningful information, that forms the foundation for achieving valuable outcomes.

Difference between PLC, SCADA and HMI

PLC, SCADA, and HMI are essential components in industrial automation that have unique roles and functionalities. While they are often used together, they each serve a specific purpose in the control and monitoring of industrial processes. Let’s delve deeper into the differences between these technologies:

1. PLC (Programmable Logic Controller):

+PLCs are specified industrial computers intended for controlling manufacturing processes and machinery.

+They carry out control functions according to logic programmed by the user, often using ladder logic or other programming languages.

+Interfacing with actuators, sensors, and various devices, PLCs monitor inputs, implement control algorithms, and produce outputs to manage machinery and equipment.

+PLCs are utilized for real-time control activities like sequencing, motion control, logic operations, and process automation on a machine or equipment level.

2. SCADA (Supervisory Control and Data Acquisition):

+SCADA systems are software applications that collect and analyze real-time data from different sources in an industrial setting.

+They offer a centralized platform for overseeing, managing, and controlling industrial processes and equipment.

+SCADA systems commonly incorporate functions like data acquisition, visualization, trend analysis, reporting, alarms, and remote access.

+By combining data from HMIs, PLCs, sensors, and other devices, SCADA systems give operators a comprehensive overview of the entire industrial process or facility.

3. HMI (Human-Machine Interface):

+HMIs are software applications or devices that serve as localized user interface, enabling operators to interact with systems or machines quickly.

+They offer a visual interface for operators to oversee processes, manage equipment, and receive information.

+HMIs usually consist of components like switches, buttons, status indicators, trend displays, alarms, and data input fields.

+These interfaces can function independently or be incorporated into SCADA systems to offer control and monitoring at the equipment or machine level.

What is SCADA and HMI in PLC systems applications?

SCADA (Supervisory Control and Data Acquisition) and HMI (Human-Machine Interface) play crucial roles in PLC (Programmable Logic Controller) systems applications. SCADA acts as a central database that stores and manages operations on a large scale, working in tandem with the PLC to automate processes, track and analyze data, and ensure remote site monitoring. HMI, on the other hand, serves as the interface that allows human operators to interact with the SCADA-PLC system through screens, buttons, levers, or keyboards, enhancing productivity, reducing costs, and improving reliability and safety in industrial settings.

In PLC systems applications, SCADA and HMI are utilized for various purposes, including:

+Monitoring and Control: SCADA and HMI systems are used to monitor and control industrial processes, machinery, and equipment remotely or locally.

+Data Acquisition and Analysis: They collect real-time data from sensors, pumps, motors, and valves, process this data, and provide insights for informed decision-making.

+Recording and Reporting: SCADA systems record events and data into files, enabling historical analysis and reporting for performance evaluation and optimization.

+Alarm and Notification: SCADA and HMI systems generate real-time alarms and notifications of operating conditions, enabling prompt responses to issues or anomalies.

+Enhancing Operator Interaction: HMIs provide a user-friendly interface for operators to interact with the system, adjust settings, and address any detected problems efficiently.

Overall, SCADA and HMI systems in PLC applications streamline industrial automation processes, improve efficiency, ensure data accuracy, and facilitate seamless communication between different components of the system, ultimately enhancing productivity and safety in various industries.