Abstract: A system and method for retrofitting manual price signs at or for highway service stations like gas stations. The present invention includes electronic LED price digits that can be replacement-inserted into slots in existing signs. In a first embodiment, digits are installed on existing sign rails after removing manual digits. In a second embodiment, digits can be installed directly inside the sign.

Abstract: A system and method for verifying that a price sign has changed a displayed price correctly including a message control system that monitors communications between a controller and controller and one or more price signs at a retail sales location like a gasoline station. One or more messages is sent to a remote location such as a monitoring point or corporate headquarters when a displayed price does not change correctly upon command or whenever the price sign is commanded to change a displayed price. A typical message may be email to one or more particular recipients. In addition to monitoring or listening-in to communications between a sign controller and a price sign, the message control system can optionally perform diagnostics to check on the health of the sign controller, the sign, or both.