4. Real time processing

Real time processing is usually found in systems that use computer control.

This processing method is used when it is essential that the input request is dealt with quickly enough so as to be able to control an output properly. The is called the 'latency'.

For example, the computer inside the Engine Control Unit in a car has to manage the engine at every moment based on what the driver wants to do.

Real time processing has to be programmed very carefully to ensure that no input events are missed.

Note that real-time processing does not have to be 'fast'.

For example, a traffic light system is a real-time system but it only needs to process data relatively slowly. On the other hand, controlling a car engine has to deal with input events happening every thousandth of a second so a very fast computer is needed to do this -but both the traffic-light and the car engine computers are carrying out 'real-time' processing.

Examples:

• Traffic lights
• Heart rate monitoring
• Aircraft control
• Computer games
• Controlling robots

The user interface of a real-time system may use specialist input devices to provide data input.. For example, a car driver will be providing input data to the onboard computer with throttle and brake pedals. A gamer may be using a joystick or hand held control to interact with the real-time game. A traffic light system may sense the car at the lights using a buried inductive loop.