DCS was "distributed" only when compared with the complex systems which dominated control rooms at the time. But these were still fairly large clumps of mini-computers, with multiple marshalling racks of wiring to field-based I/O.

With the arrival of personal computers, Ethernet and Fieldbus, everything started to get smaller and was networked. Wireless networking was supposed to get rid of the I/O racks. But how could anyone get away from wiring up hundreds and thousands of I/O points?

Emerson's Delta V was the first small PC-based DCS, introduced in 1996. The new DeltaV S-series, just introduced (Sept. 2009) includes major enhancements to all I/O processing, operator displays, asset management, batch capability and system security. But it's major achievement is a fundamental, innovative rethink of I/O wiring called "I/O on Demand".

Innovative Electronic Marshalling essentially eliminates the need for a physical path from signal-source to controller. Instead, new single channel CHARacterization ModuleS (CHARMS - cute name) relay I/O info via the Ethernet backbone to any controller, providing single channel integrity and flexibility down to the channel level.

The human-centered design approach, and the resulting "I/O on demand" architecture, is like applying the principles of lean manufacturing to the work processes around an automation project. The enthusiastic Emerson team proclaims, "After 35 years, DCS has gotten fat, and it's now time for lean. This puts the real D in DCS!"

On a typical project with say 16,000 hardwired points, I/O-on-demand alone can cut the number of cabinets by 50% and their footprint by 40%, while eliminating as much as 90% of intra-cabinet wiring. This reduces engineering time dramatically and ensures that changes to the original design can be readily accommodated without rewiring - a BIG problem with legacy DCS.

Getting rid of wires eliminates most activities associated with wiring design and installation. Cabinets, wire, terminations, cable tray design, fusing, installation drawings and a host of other activities are gone. The S-series incorporates a major enhancement for WirelessHART networks, cutting wireless network design time by about 20%.

By putting usability and productivity at the heart of product design, Emerson meets two vital needs of today's global environment: a/ Skills shortages in emerging markets; and b/ an aging experienced workforce in the developed world.

DeltaV S-Series is no ivory-tower re-think. Emerson insiders tell me that they worked the design every step of the way with a large petrochemical customer.

Bravo, Emerson team, for yet another engineering and market coup!