Jun 1, 2022

Platform-independent, efficient and expandable visualization with TwinCAT HMI

The human-machine interface is subject to increasingly stringent requirements. A machine’s operator interface should look appealing and reflect the corporate identity of the company. In addition, the user experience must meet modern expectations, with optimized programming and development times. TwinCAT HMI meets all these requirements and shapes the path for next generation HMIs.

Beckhoff was one of the first HMI providers to rely on HTML5 as the underlying technology instead of using a platform-dependent framework, as is often the case. Regardless of the operating system used, a web-based HMI can be displayed on almost any platform. The only thing needed is an HTML5-capable browser. The interface can be made to be responsive so that it automatically adapts to the resolution and orientation of different displays – that is, to a panel, tablet or smartphone.

TwinCAT HMI (TE2000) is distinguished by its modular expansion options at all levels. Application-specific controls and server extensions can be developed via programming interfaces. The product fulfills the common requirements for an HMI starting from user management, message system, internationalization up to recipe management and recording of historical data. The product is divided into HMI Creator, HMI Framework and HMI Server.

TwinCAT HMI Creator

The TwinCAT HMI Creator provides the development environment. Similar to TwinCAT 3, all tools are integrated in Microsoft Visual Studio®. Efficient engineering is an important issue in HMI development. HMI Creator follows the familiar approach of Visual Studio® graphical configuration in .NET/WPF. This enables the development of HMI interfaces without the need for prior knowledge of web technologies. However, experts still have full access to the project source code and can implement specific application requirements via the programming interfaces. The HMI Creator provides a live view to test the application in engineering or on the corresponding target device. This saves time and enables direct access to helpful diagnostic tools of the browser. Collaborative teamwork is supported for common source code control systems such as Git or TFS.

The seamless integration of TwinCAT allows the development and testing of PLC and HMI within one environment. The TwinCAT Automation Interface is also offered for TwinCAT HMI, allowing the automatic generation of the entire TwinCAT project including I/O configuration, PLC code and HMI via a programming interface (e.g., .NET). TwinCAT HMI supports Microsoft Nuget as a package management system in order to create packages for HMI components, such as control libraries or server extensions. These can be distributed via Microsoft's official Nuget server or on self-managed, on-premise Nuget servers.

TwinCAT HMI Framework

Beckhoff has developed a specific framework so the web-based user interface can also be run on devices with lower CPU performance classes. The TwinCAT HMI Framework provides communication to the development system and server, delivers a programming interface for specific requirements and a comprehensive control library. Standard controls are available that are optimized for use as machine operating interfaces. In addition, controls can be used for easy display of multimedia content (video, audio and documents) as well as controls for charts and trend display.

Specific controls for TwinCAT and TwinCAT HMI functionalities, such as the message system or recipe and user management, are also included. The TwinCAT HMI Framework can be extended with custom controls based on well-known web technologies such as HTML5, CSS, JavaScript and TypeScript. In addition, user controls can be created to combine existing controls and add logic without programming. The display of the controls can be subsequently adapted via “themes”. Graphics can be exchanged, CSS definitions can be adapted or specific display-relevant properties defined using a theme editor in the TwinCAT HMI Creator. TwinCAT HMI Framework and Server functions are accessible via an extensive API. The HMI Framework communicates with the HMI Creator and HMI Server via websockets. Interval times and access procedures may also be selected individually for the HMI server.

TwinCAT HMI Server

To be able to support all required operating systems and architectures, Beckhoff developed its own web server. The server can be used for Windows, Windows CE and TwinCAT/BSD operating systems and is provided for x86/x64 and ARM platforms. In addition, it acts as an application server for HMI and SCADA applications. The functionalities are provided in server extensions and cover the typical HMI requirements regarding PLC data access, user management and message systems. The message system of the HMI integrates the TwinCAT Eventlogger and can read out the events on several local and remote systems. The user management of the HMI Server is based on an authorization concept, where the users are allocated to different groups. In addition, the HMI Server offers the possibility of centrally logging users into an Active Directory via an LDAP server extension, so users can be managed company-wide at a central location.

Support for the TwinCAT ADS and OPC UA protocols means that all TwinCAT devices and third-party systems can be easily connected to the HMI Server. Users can add their own extensions to easily map user-specific processes. These extensions can access HMI Server functions via an extensive .NET standard API. In addition to the ability to connect multiple HMI clients and targets to the server, multiple HMI servers can exchange data with each other. The communication between HMI Server and Framework or additional servers is carried out via secure websocket connectors by default. Furthermore, custom certificates can be added for encryption, and multiple HMI Servers can be started on one system to centrally deploy multiple HMI projects.


TwinCAT HMI is under continuous development in all product areas. Therefore, efficient engineering is essential for reducing development costs. The TwinCAT HMI project generator is used to create a HMI project after selecting the template and configuring the resolution and navigation structure. The templates were designed by professional designers so usability can be further optimized in collaboration with application engineers and in specific customer projects.

The TwinCAT HMI Framework and its API will continue to be developed in the future according to project requirements and customer needs. The control library will be expanded with new controls that offer diagnostic functions. The topology of EtherCAT masters and slaves can be automatically generated via EtherCAT diagnostics and used for programming and service. In addition, TwinCAT HMI will include further components for Beckhoff products. HMI components are already available for TwinCAT Analytics, TwinCAT Scope, TwinCAT Speech, TwinCAT Vision and XTS. HMI solutions for specific industries such as entertainment and stage technology, building automation, plastics and process industries are also available.