A vital programmable logic device (VPD) is provided having at least two microprocessors. The VPD is configured to provide failsafe operation of a vital control system while operating in a closed circuit environment. In at least one embodiment of the present invention, railroad grade crossing signals are controlled by the VPD.
VITAL SOLID STATE CONTROLLER
DISPOSITIF DE COMMANDE D'ETAT SOLIDE VITAL
2015-11-10
Patent
Electronic Resource
English
VITAL RELAY ASSEMBLY WITH MODULAR SOLID-STATE CURRENT-LIMITING
European Patent Office | 2019
|NTRS | 1974
|VITAL RELAY ASSEMBLY FOR MODULAR SOLID-STATE CURRENT-LIMITING
European Patent Office | 2021
|Tema Archive | 1975