Web-based SCADA interfaces require more different approach, than regular web sites.
Why web SCADA?
– a properly designed UI can be used on any operator’s device: a smartphone, a tablet, or a desktop computer. It can be opened on any embedded kiosk device with almost any OS inside (of course, unless this OS has a web-browser).
– using a proper front-end web server/web proxy and a proper ACL setup, the UI can be absolutely securely opened from any location.
Cons: web interfaces are unstable. Sometimes seriously unstable.
In this article we will give some tips about it, no matter which web interface is built for EVA ICS or any other IoT/IIoT platform.
SCADA web interfaces are very different from regular web sites: the same web page can be opened for days or even weeks and its JS code should be always active. Unfortunately, according to our experience, web browser JS engines can not reach this goal, so it is highly recommended to forcibly reload the UI page (e.g. with old classic meta-refresh) at least once a day. To make the reload process smooth, authentication data should be kept in a local session cookie or another local data storage.
Embedded client reliability
Despite using reloads, there is always a big problem with embedded clients (mobile-OS based tablets, “smart” touch screens with embedded mobile-OS inside etc.). Unfortunately mobile web browsers don’t have long-run reliability, they contain lots of memory leaks and it is highly recommended to perform a full client reboot, at least once per two weeks.
This can be done automatically for external-powered kiosks, using a relay between the kiosk computer and a PSU and putting a nightly job into SCADA back-end or into a PLC. Dealing with tablet-based kiosks is more complicated: it is recommended to remove kiosk battery (if possible) and power it directly from the PSU.
Despite of the above, we strongly believe web SCADA solutions are future of the Industrial Internet of Things and Industry 4.0. Try EVA ICS, which has lots of tools to solve such problems out-of-the-box or ask our core team to build a turnkey Industry-4.0 setup for your business.