This International Standard provides guidance on the design principles and performance criteria for computer-based radiation monitoring systems (RMS). Such systems are provided to integrate the monitoring of plant-wide processes, effluent streams, and area radiation. This standard describes the integration of functions including equipment such as those described in standards IEC 60761-1, IEC 60761-2, IEC 60761-3, IEC 60761-4, IEC 60761-5, IEC 60768, IEC 60910, IEC 60951-1 IEC 60951-2, IEC 60951-3, IEC 60951-4, IEC 60951-5, IEC 61031, and IEC 61250 into a plant-wide digital system. The requirements of system-level components (central computer, subsystem computers, operator consoles, and interconnections) are discussed. For detection assemblies, processing units and alarm units, this standard contains only the requirements needed to allow connection into the centralized system. The standards referenced above contain the specific requirements for these components. This standard provides criteria for the interface between monitors of different safety classes. This standard integrates data processing, storage, optimization, and correlation of data flow and displays. This standard defines the communication criteria to link distributed radiation monitoring equipment in the plant with an open architecture configuration. This standard does not apply to the design and testing of detection and measurement assemblies and subassemblies except as necessary to define the interface with the plant-wide system. Certain RMS functions, or a complete centralized radiation monitoring system may be entirely implemented with direct-connected analogue/relay technology. This standard does not apply to such functions or systems