Client/Server

The TwinCAT HMI is essentially based on a client-server architecture. No additional software installation is required for the TwinCAT HMI Client. It is an HTML5-capable web browser that does not require any additional extensions. The browser connects to the TwinCAT HMI server, which provides the HMI in a virtual directory (WWW root). The HMI is passed to the client via HTTP(S) protocol. The HMI project consists of content such as pages and images and the TwinCAT HMI framework, which is based on JavaScript and dynamizes the web-based HMI. Among other things, the framework provides the controls and establishes a secure web socket connection (WS(S)) to the server in order to be able to communicate with it.

The TwinCAT HMI server has a modular structure. Additional functionalities can be provided via server extensions, such as the messaging system or other protocols. The server supports the TwinCAT ADS protocol and can therefore communicate with all TwinCAT devices. Third-party systems can be connected via OPC UA extensions.