Problem:     A leading builder of highway signs needed a controller that would allow remote control of the prices shown on interstate gasoline signs. The system needed to be modular since the number of products to be displayed varied from sign to sign and the system required a number of wide area networks to meet specific site needs.

Solution:     The sign's digits are written on scrolls of material that are positioned by two motors. The digits range in height from 4 feet to over 8 feet. Each product, (diesel, unleaded, etc) has a controller that controls the scroll's position so that the proper price is shown on the display. A unique sensor arrangement allows for precise digit positioning even in the harsh environment that these signs are subjected to.

The system uses a product controller to control a single product's price for both sides of the sign. It controls all the motors/positioning associated with the digits for both sides of the sign. The product controllers communicate with the central controller across a twisted pair LonWorks network. The central controller provides system power and acts as a communications interface to a hand held programming device, the POS system used within the gas station and a number of wide area networks. The sign's main controller emulates a Gilbarco gasoline dispenser so that when the POS updates the gas prices at the pump, the sign's display is automatically updated to reflect the change. The system supports several wide area networks including cellular modem and satellite.