The term "Deterministic" is often confused with "Synchronous" when referring to Industrial Ethernet. My article explains this difference and hopefully will correct the improper usage of the terms. I have also included lots of technical information about Industrial Ethernet.  See this article: https://drive.google.com/open?id=0B27D2cPp6ETMSU1JcFJGelUwV0U

Dick Caro

New Process Control Inflection Point

Much as the introduction of the DCS by Honeywell in 1976 changed the process control industry, a new movement initiated by ExxonMobil promises to change the industry in the next two years. Yesterday, January 26, 2016 Lockheed Martin engaged by ExxonMobil gathered together potential suppliers of process control systems to hear a series of presentations detailing the kind of system that ExxonMobil, and probably many other process industry manufacturers want to buy - and it does not look much like today's DCS products.

The situation encountered by ExxonMobil and many other companies in the Chemical, PetroChem, and Oil and Gas industries is partial obsolescence of their DCSs, many installed 30-40 years ago. While is has been difficult and expensive to keep these antique systems operating, rip and replace has not been an economical option. The problem is that the components of the DCS are so tightly intermeshed that partial update becomes impossible. In many cases, new custom made electronics is being installed where components can no longer be repaired, thus keeping alive a control system with 40 year old technology. ExxonMobil and others does not want to repeat this in the future, and is willing to set the pace to change the industry in such a way that it will not be repeated.

Needless to say, the DCS companies are not exactly in favor of this sea-change to process control system architecture. Hints of this change were presented at the February 2015 ARC Forum held in Orlando, but details were only released yesterday at the meeting called by Lockheed Martin. All DCS suppliers were invited along with many non-traditional industry suppliers who might build parts or all of the new architecture.

Stay tuned to this Blog as the development continues.

Dick Caro, CAP, ISA Fellow

CEO CMC Associates

Just in case you haven't been following the controversy on ControlGlobal.com, I have published three articles in which I have claimed that using a variable frequency drive (VFD) to control the speed of the electric motor driving a centrifugal pump is actually superior to using a traditional control valve with an electro-mechanical actuator and positioner. It saves energy because the pressure drop across the valve is gone. On new installations, the pump and motor may be smaller due to the reduced head requirement. Maintenance is reduced because there is no stickiness with the VFD as there is with control valves. There are no fugitive emissions through the seal on the no longer existing control valve stem. Finally, the quality of control is actually improved since the VFD responds instantly to PID output changes, and there is a perfectly linear relationship between pump rotational speed and flow rate. Still to be proven are the effects on turn-down ratio, lack of VFD support of Foundation Fieldbus, and lack of actual user feedback in real loop control situations.

Has anybody actually tried this in a real control loop?

This blog is devoted to any of my favorite topics:

1. Industrial Wireless Networks (also called wireless sensor networks)

2. Fieldbus - meaning Foundation Fieldbus for process control

3. Variable Frequency Drives (VFDs) used to replace/substitute for process control valves

Post your questions/answers here.