Manufacturing Message Specification
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Manufacturing Message Specification (MMS) is an international standard (ISO 9506) dealing with messaging system for transferring real time process data and supervisory control information between networked devices and/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 and/or controlling these objects.
- A set of encoding rules for mapping these messages to bits and bytes when transmitted.
[edit] MMS original communication stack
MMS was standardized in 1990 under two separate standards as
- 1. ISO/IEC 9506-1 (2003): Industrial Automation systems - Manufacturing Message Specification - Part 1: Service Definition
- 2. ISO/IEC 9506-2 (2003): Industrial Automation systems - Manufacturing Message Specification - Part 2: Protocol Specification
The original communication stack of MMS is as shown below
| Application | Association Control Service Element ( ACSE )- ISO 8649/8650 |
| Presentation | Connection Oriented Presentation - ISO 8822/8823
Abstract Syntax Notation (ASN)- ISO 8824/8825 |
| Session | Connection Oriented Session - ISO 8326/8327 |
| Transport | Connection Oriented Transport - ISO 8072/8073 |
| Network | Connectionless network - ISO 8348 |
| Link | MAC - ISO 8802-3 [Ethernet]
MAC - ISO 8802-4 [Token Ring] |
| Physical | Ethernet
Token Ring |
[edit] MMS stack over TCP/IP
As the original MMS stack was completely over heavy ISO layer, it was never got popularized. In 1999, Boeing decided to replace relevant 4 layers of ISO with TCP/IP. They introduced ISO Transport over TCP (RFC 1006) to have interaction between the top ISO layers of MMS to the bottom TCP/IP layers. This had revolutionized MMS into a globally accepted standard. MMS stack after this adoption is as shown below
| Application | Association Control Service Element ( ACSE )- ISO 8649/8650 |
| Presentation | Connection Oriented Presentation - ISO 8822/8823
Abstract Syntax Notation (ASN)- ISO 8824/8825 |
| Session | Connection Oriented Session - ISO 8326/8327 |
| Transport | ISO transport over TCP - RFC 1006
Transmission Control Protocol (TCP) - RFC 793 |
| Network | Internet Control Message Protocol (ICMP) - RFC 792
Internet Protocol (IP)- RFC 791 Address Resolution Protocol (ARP)- RFC 826 |
| Link | IP datagrams over Ethernet - RFC 894
MAC - ISO 8802-3 [Ethernet] |
| Physical | Ethernet |
