Single loop farewell?

A hybrid controller, combining sequential and three term functionality could herald the demise of the single loop controller. Paul Gay previews the launch of Procidia

Unit controllers used in industry today need sequential control, continuous loop control and sometimes batch control. Current control technology has certain limitations. Distributed control systems, although very powerful, are often too expensive. PLCs are not ideally suited to loop control even though many models have PID cards as optional extras, writes Paul Gay.

An ideal solution would be a controller capable of loop control with PID and a discrete controller in one cost effective system. To this end, Moore Process Automation Solutions has developed a unit controller offering cost effective continuous, batch and discrete open automation solutions. Procidia has been designed to serve unit and small plant applications that currently fall between higher cost DCS and poorly integrated PLC/Loop controller solutions. The system greatly reduces engineering costs by using the World Wide Web (WWW) to provide powerful tools and services for specifying, start up and maintenance. Procidia is made up of plug and go components that are auto recognised to provide instant operation and features a comprehensive on-line library of control algorithms and pre-configured solution packages for common applications that further reduces configuration effort.

A controller, called ipac, at the heart of the system provides advanced continuous, discrete and batch control with multiple communications protocols. High density, intelligent input/output modules automatically configure the system to accept them on insertion. The controller software, called iware, is a Windows 95/98/NT auto-configuring HMI package that uses the same database as ipac to eliminate extra configuration. It provides a wide range of pre-configured point and overview displays with real-time trending, alarm handling, recipe management and data logging. Each controller accepts up to 250 I/O and supports up to 25 control loops each of which may be either discrete or continuous. Up to 32 controllers can be used together to create unrivalled scaleability from cost effective systems with just a few I/O up to 8000 I/O.

INTERNET READY

The software is OPC compliant and has Internet communications for remote operation and configuration. Tag support is essentially unlimited. A touch screen Pentium PC operator station, called istation, also provides Ethernet and web connectivity while providing multiple graphical configuration languages based on IEC61131 and featuring on-line configuration viewing to aid start up and trouble shooting. A web server connects controllers directly to the Internet and embedded graphics, protected by multi-level security, allow multiple users full or restricted remote access to data or control without separate HMI software.

The Procidia concept includes extensive WWW centric tools and services to help get applications running in the fastest possible time. Software called istore provides on-line technical information and design wizard and accepts orders over the web. It also allows the specifier to track an order on-line. Another package, called ixpert, is an on-line, real-time connection for start up, trouble shooting and equipment set up. Engineers can view and trouble shoot configuration and equipment set up remotely, then download and install changes for fast resolution of problems.

Procidia units communicate with each other and with existing Moore 353 and 354 controllers in real time using Moore’s deterministic LIL protocol or via the open communications protocol Modbus. Integration into plant wide automation schemes for individual or groups of Procidia systems is quickly and simply accomplished by Ethernet connections using OPC.

Procidia will be available in the UK only from Able Instruments.

Mike Eyre, Moore Process Automation Solutions Tel: 01935 470127; http://moore-solutions.com

Jon Spalding, Able Instruments & Controls Tel: 0118 931 1188; http://www.able.co.uk