Instem: The Aberthaw Project

Instem Computer Systems,Walton Industrial Park, Stone, Staffordshire, UK

The Aberthaw project was my third major project during my four years at Instem (1989-1993); a new automated Boiler Control system for Aberthaw coal-fired power station in South Wales.

The Aberthaw project team consisted of some members of the Littlebrook team plus some new boys on the block. As well as myself, the team included Colin Day, Graig Powers, Mark Rudolph, Duncan Reade, Mark Bilton, Matthew Andrews and Darren Lovatt.

On this project I configured, customised and managed the National Power Generic Cutlass system software, a purpose-built, PDP-11-based, distributed, real-time operating system, database, and programming language. For each of the three turbines, there was a network of ten to twelve PDP-11 industrial computers; half for monitoring and control functions and half used to drive graphical displays and touch screens.

I-Range Enhancements

Instem's I-Range data acquisition subsystems and devices were enhanced by the addition of a pulsed output card designed especially for the Aberthaw project. One of my tasks was to upgrade the configuration software to recognise and configure the new card. This software was my first experience of state-machine driven software and was an interesting mini-project.

Generic CUTLASS

Cutlass was the old Central Electricity Generating Board's realtime, operating system, programming language and database. It had some fascinating features such as three state logic (true, false, and null (known as bad)). There were explicit were subsets of the language for particular tasks including closed loop monitoring and control, state-machine driven supervisory control, and user interface display and input device control.

Generic Cutlass was a set of pre-processors, script files and skeleton algorithms. An administrator used a set of configuration programs to set up some scripts that generate scanning software routines, event generation, and handling routines, etc for the contents of a supplied database. Guess who got this administrative role? Generic Cutlass was an impressive system considering it was based on completely, out-of-date hardware. Attempts to port the language to more up-to-date processors had failed.

Allen Bradley PLC's

Allen Bradley Programmable Logic Controllers (PLC)'s had a 'new' module which allowed for communication between the PLC and a PDP, I wrote software to retrieve values from the PLC's and populate the Cutlass database.

After Aberthaw I was really looking forward to getting back to a more modern set of equipment and software languages and tools. The EME/MEB project provided that.