MMS (Manufacturing Message Specification)

MMS (Manufacturing Message Specification)
Name	MMS (Manufacturing Message Specification)
Status	Standard
Organization	International Organization for Standardization
Abbreviation	MMS
First published	1990s
Related	ISO/IEC 9506, ISO 8802-3, IEC 61850, OPC UA

MMS (Manufacturing Message Specification) is an international application layer protocol standard for real-time messaging in industrial automation that defines services for monitoring and control of manufacturing devices. It standardizes object models, service primitives, and encoding rules to enable interoperability among devices from different vendors in sectors such as process control, power generation, and discrete manufacturing. The specification is maintained within international standards bodies and is commonly used alongside networking, transport, and security standards in automation deployments.

Overview

MMS is defined by the International Organization for Standardization and the International Electrotechnical Commission under ISO/IEC 9506 and is designed to operate over stacks specified by organizations such as the Institute of Electrical and Electronics Engineers, the Internet Engineering Task Force, and the International Telecommunication Union. Key concepts include a rich object model for industrial entities, a set of abstract services for read/write/subscribe semantics, and mappings to concrete encodings and transports used by vendors including ABB, Siemens, Schneider Electric, Honeywell, and General Electric. The standard's object-oriented approach aligns with modeling work from institutions like the Open Group and integrates with protocols referenced by the Electric Power Research Institute and associations such as the OPC Foundation.

History and Development

The standard emerged through collaboration among national standards committees involving organizations such as the British Standards Institution, Deutsches Institut für Normung, and the American National Standards Institute, with input from industrial participants including Emerson, Yokogawa, Mitsubishi Electric, and Rockwell Automation. Early development paralleled innovations in networking by Xerox PARC, Bell Labs, and AT&T, and was influenced by telecommunications frameworks produced by the ITU‑T and packet switching research from DARPA. Subsequent revisions incorporated lessons from fieldbus initiatives led by Canbus International, PROFIBUS Nutzerorganisation, and the International Electrotechnical Commission’s working groups, while academic contributors from Massachusetts Institute of Technology, Stanford University, ETH Zurich, and Technische Universität München informed formal modeling and verification techniques.

Protocol Architecture and Services

MMS defines an abstract service model with primitives categorized into naming, data access, file transfer, event reporting, and control operations; its architecture is comparable in layering to stacks specified by IEEE 802 and ITU‑T X.200 series. The specification prescribes association establishment, service invocation, and confirmation flows that echo session management approaches from X/Open, and maps these services to encodings from the International Organization for Standardization and ITU-T's ASN.1. Implementers often reference guidance from the Internet Engineering Task Force, the World Wide Web Consortium, and the Open Systems Interconnection model when integrating MMS into larger automation architectures deployed by companies like ABB, Siemens, Toshiba, and Hitachi.

Data Models and Object Types

The MMS object model includes named variable, domain, and file objects, modeled to support attributes, access control, and type definitions; this modeling approach parallels information modeling used in IEC 61850, DNP3, and OPC UA. Typical object types implemented by vendors such as Schneider Electric, Yokogawa, and Honeywell include analog input, analog output, counter, and event log, and the model supports complex structured types comparable to those used in database systems developed at Oracle, IBM, and Microsoft Research. The model's emphasis on clear naming and scoping has been adopted in projects at Siemens, General Electric, and ABB for asset management, historian integration, and supervisory control systems developed by companies like Emerson and Mitsubishi Electric.

Communication Profiles and Mappings

To achieve interoperability across physical and link layers, MMS specifies mappings to transport protocols such as TCP/IP and ISO TP4, and to data encodings like ASN.1 Basic Encoding Rules; these mappings are applied in products from Rockwell Automation, Schneider Electric, and Siemens. Industry profiles produced by consortia including IEC technical committees, the OPC Foundation, and vendor alliances define constraints and options for using MMS in contexts such as power substations, process plants, and manufacturing lines. Integrations often involve gateways and converters developed by companies like Moxa, HMS Networks, and B&R Industrial Automation to bridge MMS to protocols including Modbus, PROFIBUS, EtherNet/IP, and OPC UA.

Security and Reliability Features

Security considerations for MMS deployments reference cryptographic and authentication mechanisms standardized by organizations such as the Internet Engineering Task Force, the National Institute of Standards and Technology, and ISO/IEC, and are implemented in products from Siemens, ABB, and Schneider Electric. Reliability features include association supervision, heartbeat monitoring, and confirmable service primitives suited to high-availability environments like power utilities and petrochemical plants managed by companies such as GE Energy, Honeywell, and Yokogawa. Standards for secure remote access and auditing produced by bodies like the Center for Internet Security and the Industrial Internet Consortium inform hardening practices and certification efforts in critical infrastructure projects overseen by utilities and grid operators.

Implementations and Industry Adoption

MMS is implemented in SCADA systems, distributed control systems, and substation automation products from vendors including Siemens, ABB, Schneider Electric, Honeywell, and General Electric, and is used by energy companies, refineries, and manufacturing firms. Integration work by system integrators and service providers including Schlumberger, Fluor, Bechtel, and Jacobs Engineering integrates MMS-capable devices into larger automation and asset management solutions. Academic and industrial testbeds at institutions such as ETH Zurich, TU Delft, KTH Royal Institute of Technology, and the University of California have evaluated MMS interoperability, scalability, and performance in conjunction with technologies from Cisco Systems, Intel, and Huawei.

Category:Industrial automation standards