Microprocessor Interlockings: Designing Network Equations

摘要

Railroad Signal Systems have evolved over the years to be one of the safest systems in the Transportation Industry. With the expanding use of microprocessor based interlocking systems, the implementation of signalling logic using Boolean equations needs to be done with methods that retations needs to be done with methods that reatin the inhernt safety in designs previously achieved using vital relays. Most circuits used in signalling can be represented quite well using Boolean logic. However, the author has found that networks, such as route check, home, and distant networks used extensively in Railroad Signalling, pose a unique set of problems when they are represented in Boolean logic using conventional methods. These problems are especially severe when implementing the larger three or four track interlockings.