Manufacturing Message Specification (MMS) is an international standard (
ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
9506) dealing with messaging systems for transferring real time process
data
Data ( , ) are a collection of discrete or continuous values that convey information, describing the quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted for ...
and supervisory control information between networked devices or computer applications. The standard is developed and maintained by the ISO Technical Committee 184 (TC184). MMS defines the following
* A set of ''standard objects'' which must exist in every device, on which operations like read, write, event signaling etc. can be executed.
Virtual manufacturing device (VMD) is the main object and all other objects like variables, domains, journals, files etc. comes under VMD.
* A set of ''standard messages'' exchanged between a client and a server stations for the purpose of monitoring or controlling these objects.
* A set of ''encoding rules'' for mapping these messages to bits and bytes when transmitted.
MMS original communication stack
MMS was standardized in 1990 under two separate standards as
# ISO/IEC 9506-1 (2003): Industrial Automation systems - Manufacturing Message Specification - Part 1: Service Definition
# ISO/IEC 9506-2 (2003): Industrial Automation systems - Manufacturing Message Specification - Part 2: Protocol Specification
This version of MMS used seven layers of
OSI network protocols as its communication stack:
MMS stack over TCP/IP
Because the
Open Systems Interconnection
The Open Systems Interconnection (OSI) model is a reference model developed by the International Organization for Standardization (ISO) that "provides a common basis for the coordination of standards development for the purpose of systems inter ...
protocols are challenging to implement, the original MMS stack never became popular. In 1999, Boeing created a new version of MMS using
Internet protocols
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are ...
instead of the bottom four layers of the original stack plus RFC 1006 ("ISO Transport over
TCP") in the transport layer. The top three layers use the same OSI protocols as before.
In terms of the seven-layer
OSI model
The Open Systems Interconnection (OSI) model is a reference model developed by the International Organization for Standardization (ISO) that "provides a common basis for the coordination of standards development for the purpose of systems inter ...
, the new MMS stack looks like this:
With the new stack, MMS has become a globally accepted standard.
External links
MMS Protocol DetailsMMS OverviewMMS V1 Abstract Syntax* MMS Protocol Description
* MMS. Presentation by Prof. Dr. H. Kirrmann, ABB Research Center, Baden, Switzerland
{{ISO standards
ISO standards