According to a recent report by Venture Development Corp., the total market for distributed and remote I/O devices used with distributed control systems (DCSs), programmable logic control (PLC) and PC-based control is expected to grow 8.3% each year to US$2.8 billion in 2003 from US$1.9 billion in 1998.

PC-based systems growth to displace many current DCS and PLC systems

The report, "Global Markets and User Needs for Industrial Distributed/ Remote I/O, " predicts that the growth of PC-based systems is expected to displace many current DCS and PLC systems. It states that the market for remote and distributed I/O products used only with PC-based systems is projected to grow by 19% per year from US$201 million in 1998 to US$476 million in 2003; or 11% of 1998's total market to about 17% of 2003's total market.

Openness lets users buy components from multiple sources

Worldwide Distributed/Remote I/O Shipments (% of dollar volume)

Source: Control Engineerig with data from Venture Development Corp.

Though use of PC-based control for real-time process and machine control has often been limited by nondeterministic operating software and perceived unreliability, user interest in the openness of PC-based systems is growing. This openness lets users buy components from multiple sources, which helps lower prices and improve services; select optimal products for applications; use products from different suppliers without extensive retraining; and interface more easily with other systems for data collection.

The report adds that increased adoption of PC-based control systems is aided by software suppliers providing soft PLC and soft DCS solutions on PC-based architectures and open-networking protocols. Much of this software is being written for Microsoft Windows NT and Windows CE operating systems.