Linking Paradigms in Safety Critical Systems.

A fuel dispenser includes fuel delivery components located in a service station, a card reader for reading customer credit or debit cards, a customer data input mechanism, and a video infeed line for infeeding a video signal including advertising of a product available for sale at the service station and data about the advertisement in a closed-captioning portion of the video signal. The dispenser also includes a video display screen arranged to receive the video signal and display the advertisement as a visible video program, a memory of information about products that may be advertised, and a data controller adapted to control data for the card reader and capable of reading data from the closed-captioning portion of the video program for use in a manner independent of affecting the way the visible video program is displayed. The data may, for example be used to count the number of times a particular video program is shown; trigger a product price display on the video display screen from the memory when an advertisement of a selected product is being displayed, or indicate data input options to enable the customer to purchase the advertised product.