Multi-server web industrial facility monitoring by only COTS browser's existing functionality

This paper studies an architecture of multi-server Web industrial facility monitoring systems using only commercial-off-the-shelf (COTS) Web browser's existing functionality. First we introduce our original method of background change-of-state (CoS) communication while the user interface is focusing to a currently-connected foreground Web server. The method makes it possible for currently-not-connected background Web servers to push a CoS message to the COTS browser. Next, we show our automatic recovery method from COTS browser's communication errors and our experiment results of COTS browsers' long-term memory leaking characteristics.