Includes principles of design, construction and testing of safety logic assemblies used in protection systems. Gives recommendations for the implementation of the general principles of nuclear reactor instrumentation in IEC 60231A. It includes provisions for acceptance and in-service testing reliability criteria and protection from external influences. Safety logic functions performed within the safety logic assemblies are not included. IEC 60744 is no longer up-to-date and will not be revised by IEC. The standard is maintained for the time being for bibliographical purposes and because it was used in the past for the design of nuclear power plants which are still in operation.