A HTML5 Web Interface for JAVA DOOCS Data Display

JAVA DOOCS Data Display (JDDD) [1] is the standard tool for developing control system panels for the FLASH facility and European XFEL. The panels are mainly started on DESY campus. For remote monitoring and expert assistance a secure, fast and light-weight access method is required. One possible solution is using HTML5 as transport protocol, because it is available on many common platforms including mobile ones. For this reason an HTML5 version of JDDD, running in a Tomcat application server, was developed. WebSocket technology is used to transfer the panel image to the browser. In the other direction, mouse events are sent back from the browser to the Tomcat server. Now thousands of existing JDDD panels can be accessed from remote using standard web technology. No special browser plugins are required. This article discusses the general issues of the webbased interaction with the control system such as security, usability, network traffic and scalability, and presents the WebSocket approach.