Dedicated to improving your control systems with Process Control System models
About Control
What's new
Our Clients
About Diagrams
Automation Models
Online manual
Free Software
Other Downloads

Curious about Control Engineering?

Below we provide some links to Control Engineering resources, but first, a word about Control Loops:

The principle is simple - if you can measure  something in a process and also do something that affects that process in a predictable way then keep checking it and do whatever you can to improve it. If you know how your actions affect the process then you may be able to calculate what actions to take. It's called Feedback.

And the best explanation is a diagram.

Diagram of a Control Loop (3234 bytes)

There are many applications of control systems - probably more than you realise. You are full of control loops yourself - biological control loops

Eating when you feel hungry
Moving a glass from a table to your lips
Driving a car. How do you think you keep on the road. There is feedback - your Eyes measure the process -, your brain works out what to do and directs the- steering wheel

The control systems this site deals with are those related to engineering systems in manufacturing plants - we call it process control.

One of the most popular types of control is called PID - Proportional, Integral, and Derivative. This mostly handles  continuous control of a single variable such as temperature. 

Controlling complete factories requires much more than a few PID loops

See also S88 Links for links concerning Batch Control systems.

Academic and Independent Resources

Control System Providers

There are many businesses that provide equipment and standard (shrink wrapped) software. Some are large and some are small. We believe that small can be wonderful, and that wonderful can also be big. Here is a mix of the small and the large.

Systems Integrators

  • Specify the equipment and standard (shrink wrapped) software
  • build or get built the hardware
  • provide the application software

Some of the large control system suppliers do much of the integration for the systems they sell. This is especially true of DCS suppliers. But there is also a collection of, generally smaller, companies that just provide systems integration, using equipment and software from the PLC and SCADA suppliers. Examples and ControlDraw users are Knott Automation Projects Limited in the UK, the AN Group in Denmark, Benima/F in Sweden,  EnteGreat in Canada.


As represented by Francis of ControlDraw Ltd, Knott Automation Projects Limited, also in the UK, Jean Vieille in France

News and Information

ControlGlobal from  CONTROL MAGAZINE

The Readout Instrumentation Signpost from Ireland.

The APC Network provides a good collection of Advanced Process Control resources