Dan Hoffman, Professor
Department of Computer Science
University of Victoria
Victoria, BC Canada
Worlds in Collision: Ethernet and the Factory Floor
Over the past ten years industrial control systems have seen a significant increase in the use of computer networks and related Internet technologies to transfer information from the plant floor to business computer systems. For example, most industrial plants now use networked servers to allow business users to access real-time data from the distributed control systems (DCS) and programmable logic controllers (PLC). There are also many other possible business/process interfaces, such as using remote Windows sessions to the DCS, or direct file transfer from PLCs to spreadsheets. Regardless of the method, each involves a network connection between the process and the business systems.
At the same time, there has been an explosion in the use of Ethernet and TCP/IP for process control networks. For many years the control systems used proprietary industrial networks, giving them a considerable degree of protection from the outside world. Today many DCS and PLC systems use protocols like Ethernet, TCP/IP, and HTTP as a critical component of their architecture, resulting in easier interfacing at the cost of less isolation and security.
While technologies such as Ethernet and TCP/IP have made the interfacing
of industrial equipment much easier, there is now significantly less isolation from the outside world. Network security problems from the business network can be passed on to the process network, putting industrial production and human safety at risk.