Safety-implemented circuits must be control reliable as mandated in U.S. and European standards. Control reliability is not provided by simple redundancy. There must also be monitoring of the safety circuitry to assure that redundancy is maintained. Monitoring may be achieved by using Omron STI safety monitoring relays that range in function from two-hand palm button control to dual channel input units with time-delayed outputs that conform to ANSI B11.19-2003, Section 6.1 for Performance of the Safety Related Function(s). All manufacturer of safety relays carry the CE mark and are designed to incorporate three points of safety in their operation to meet both European and U.S. requirements. All safety relays are UL and C-UL listed.
