Mr. Brügger, when do web HMIs cause problems and what are the consequences?

Peter Brügger: Older web HMIs that are based on Java applets and are no longer supported by common browsers often cause complications. It is also difficult when several automation systems are running in one plant and an operating station has to switch back and forth between the different web servers. In such a scenario, there are usually several user levels in an operating system, for which you first have to identify yourself. However, if you jump from one web server to another, this information is lost and the login procedure starts all over again. Another important point is pop-up messages. If these are generated on a web server other than the one currently being displayed by the panel, the browser will not even notice this error.

And how can you counteract these problems?

Peter Brügger: With our 'SpiderControl AutomationBrowser' from Ininet Solutions. For example, a so-called station list can be created directly in it, in which all connected controllers are stored with their URL. The difference to a 'Favorites' list - as known from a conventional browser - is that the browser on the panel should be operated in so-called 'kiosk mode' - i.e. 'full screen' - and all normal functions of the browser menu cannot be accessed. Only the station selection and possibly a 'Back' button are displayed. The station list can also be displayed in a touchscreen-friendly and relatively large format to increase user-friendliness.

And the answer to the annoying log-in problem is called 'single sign-on'. The AutomationBrowser is able to save the log-in status on a PLC and the associated passwords. It uses the password of the current user when the user switches to another controller. If the user logs out, the password is also deleted for security reasons. If a new user arrives, the password is requested once, saved and automatically used for logging in on all controllers until the operator logs out.

And how do you solve the problem of compatibility with older web HMIs?

Peter Brügger: Several browsers have been integrated into our solution for this purpose. Ultimately, the appropriate viewer is selected invisibly for the user, which means that older Codesys V2 web visualizations, for example, can be integrated without any problems.

What else has been implemented?

Peter Brügger: The topic of 'collective alarms' also plays an important role. The AutomationBrowser can be configured so that it monitors certain variables from each controller cyclically and automatically jumps to an alarm overview in the event of an alarm status so that the user can react promptly.