AX-S4 61850 ("Access for IEC 61850" and formerly called "AX-S4 MMS") is a complete ready to run IEC 61850 interface for Windows applications. AX-S4 61850 includes an IEC 61850 client supporting OPC, an interactive object explorer for device testing and setup, IEC 61850 server functions for implementing data concentrators and gateways, and a GOOSE OPC server for publishing and subscribing to IEC 61850 GOOSE messages. AX-S4 61850 makes using IEC 61850 for OPC applications easy by simplifying the controls and reporting functions of IEC 61850 via an interface optimized for OPC applications. AX-S4 61850 supports all IEC 61850 ACSI services for reporting, controls, logical devices, logical nodes, variables, datasets, object discovery, logs, files, and GOOSE multicast messaging.