One-way data transfer for PLC to VME status reporting at the Advanced Photon Source☆

Abstract The Personnel Safety System for the experimental beamlines at the Advanced Photon Source will use a large number of Allen Bradley Programmable Logic Controllers (PLC) to replace conventional relay logic. PLCs allow for the design of a very advanced safety system that can handle a large number of I/O points. Certain situations require monitoring of the safety system from various locations around the storage ring via the EPICS OPI (operator interface) consoles. This presentation covers the chosen method for transferring data from the Personnel Safety System into an EPICS database. Specifications on PLC ladder design, EPICS database design and hardware selection are also discussed.