Manufacturing Message Specification Research Articles

Enhancing numerical controllers, using MMS concepts and a CORBA-based software bus

Open Manufacturing Equipment is mandatory to answer the demand of modern manufacturing for distributed monitoring or automation, and to allow fast system reconfiguration. This project is inspired by the reference models defined by the ISO/OSI Manufacturing Message Specification for remote machine tool supervision (MMS) and the Open System Architecture within Control Applications (OSACA). Instead of proposing MMS or OSACA protocols for communication, we propose a unified object-oriented solution based on the OMG-CORBA software bus. Adopting a common object-oriented approach for both remote communication and internal architecture of a NC platform is conceivable. It leads to a design very close to the one proposed in the mentioned standards. The consequences of including a Manufacturing Object Messaging System on the NC design model are discussed. A Java- and CORBA-based demonstration prototype has been developed. Finally, the paper describes how we address real-time constraints on communications.

Component oriented control architecture: the COCA project

The object-oriented CORBA communication protocol is used to implement the ISO manufacturing message specification (MMS) in a distributed object oriented manner. This brings operating system independent communication capabilities to devices such as NC machine-tools and to the various technical management applications expected in modern workshops, even of small size. Implementation of MMS concepts in the CORBA environment is particularly discussed. Prototype development is under course in an effective industrial platform.

Micromms: A compact abstract syntax for MMS

MMS (Manufacturing Message Specification) was initially designed for interconnection of industrial devices in manufacturing and process control applications. MMS can also be applied to new areas such as building automation, field buses and remote meter reading. Such applications have much stronger constraints concerning the available processing power and memory. The use of an MMS specified in ASN.1 and its associated Basic Encoding Rules (BER) can be questioned for such applications. ASN.1 and BER very often lead to long messages (PDUs) that require a time consuming encoding or decoding process. The purpose of this study is to define a new abstract syntax for MMS that offers the same functionality as the standard MMS abstract syntax but that leads to shorter PDUs. The principle adopted is that the essence of MMS is not in its abstract syntax but in its service definition, namely the set of MMS objects, services and parameters defined in ISO/IEC 9506-1. >

Integrating multimedia communications into an MMS environment

This paper presents an approach of network resource management in a heterogeneous manufacturing LANs environment in order to integrate multimedia services. The primary objective is to define a uniform communication interface with which the multimedia functionality can be integrated into the distributed manufacturing applications. The proposed model extends the Virtual Manufacturing Device (VMD) concept defined in the international standard Manufacturing Message Specification (MMS) in order to virtualise the communication systems. A virtual server, named Virtual Communication Support (VCS), is defined to provide the transparent services on the QoS (Quality of Service) parameters negotiation, the communication channel establishment/termination and QoS monitoring in a standardised constrained industrial communications framework. Multimedia application and traditional manufacturing applications have to co-exist in a standardised MMS environment. Furthermore the VCS model provides the support for the possible real-time extension of MMS. A platform of implementation, named PLACOMAP, is presented to illustrate a multimedia enhanced manufacturing application in a heterogeneous communication context where different types of networks, ATM, ETHERNET and MAP are involved.

Petri net modelling and design of task oriented messaging system for robot control

Manufacturing Message Specification (MMS) is an international standard for shop floor machine control. It defines a set of conceptual schema and an interactive software object known as Virtual Manufacturing Device (VMD). Many systems have been established using this protocol but very few formal methods have been used to build such systems. This paper addresses the problems of the design and analysis of a network-based task oriented messaging system for flexible robot task control using a Petri net. The information and message transfer processes of the MMS systems were analysed. The modelling methodology allows a top down approach by which the net model is decomposed into fine details with clear identification of components which can be realised directly from the model. This approach is illustrated in this paper by a Windows-based robot control prototype system implemented from the Petri net model. The prototype was built using Object Windows Library and the NetBIOS session layer protocol on a PC network.

Standard based framework for the of manufacturing control development systems

A Manufacturing Control Systems CASE tool, called MCSTOOLS, has been developed with the aim of reducing the effort needed to produce this kind of software. The control systems developed by means of this tool follow the Control Systems for Integrated Manufacturing (COSIMA conceptual model (ESPRIT 477 project). In order to minimize the development time of Manufacturing Control Systems (MCS), this CASE tool automatically generates as much software as possible . In addition, the software produced by the MCSTOOLS is highly reusable, as it conforms to a widely accepted software engineering method- Object Oriented Analysis/ Design/ Programming (OOA/ D/ P- and several manufacturing and communications standards. Among these standards the most relevant are; Product Data Representation and Exchange (also known as STEP, ISO 10303), Manufacturing Message Specification (MMS, ISO 9506) and the Common Object Request Broker Architecture (CORBA). In order to achieve the objective of producing MCSs able to be adapted to a wide range of manufacturing environments, seve ral techniques have been incorporated into the software generated by the CASE tool. The most important of these techniques are: Object oriented distributed computing, object oriented multithreading computing and object persistence. In addition, the software produced includes a Coloured Petri Net based state control module and a generic user interface written in Java. The MCS CASE tool developed can be used in different ways depending on the number of new system elements to be controlled and the complexity of this system. So in some situations it is possible to generate the control software automatically without manual assistance by using the graphical user interface of MCSTOOLS. In other cases it is also necessary to modify or to develop software using high level directives and macro language constructs included in the CASE tool. Whereas for the remainder of cases, as for other systems, it is necessary to modify or develop C++ software. When needed, new source code is developed out of a skeleton generated by the CASE tool.

Design and implementation of an MMS environment on ISODE

Manufacturing message specification (MMS) is an ISO OSI application layer standard designed to support messaging communication to and from programmable manufacturing devices in computer-integrated manufacturing environment. This paper describes a non-proprietary MMS over TCP/IP solution known as an MMS Environment. The MMS Environment consists of an MMS communication systems, a set of MMS-Interface (MMS-I) application program interfaces and an MMS Gateway for integrating non-MMS-compatible manufacturing devices into the standard MMS communication environment. The capability and resources of the real devices were modeled as Virtual Manufacturing Devices. The MMS Environment is developed on ISO Development Environment (ISODE), a non-proprietary implementation of OSI upper layers over TCP/IP. This paper will also describe the implementation of the MMS Gateway and the modeling of a Programmable Logic Controller.

Distributed cell controllers using colour Petri-nets and Fieldbus : An application in flexible assembly

In this paper, a reference system architecture is presented which utilizes colour Petri-nets (CPNs), a distributed Fieldbus sensory network and the manufacturing message specification (MMS) modelfor the control of the flexible assembly system (FAS)over a distributed communication network.In this architecture, a client and server methodology based on the MMS is utilised where the robots and the conveyor systems are modelled as servers and a CPN based cell controller is modelled as a client which is capable of dispatching the assembly task requirement to the remote devices in a timely, conflict and deadlock free manner. One of the distinct features of the proposed controller is the provision of high level interfaces for the definition and configuration of both the assembly task requirement and the structure of the assembly system. It makes the system highly effective for small batch production where reconfiguration of the physical system is frequently needed. A case study is presented to demonstrate a real application of the proposed system.

Conceptual design of a shop floor control information system

This paper presents a conceptual model for guiding the integrated design and implementation of a shop floor control information system SFCIS in manufacturing. Issues discussed include control decisions, information flow, and communication message passing, but not the content of specific shop floor databases. A bidding system is assumed for control of job dispatching and routeing. Information flow is described using IDEF0. Through an object-oriented O-O approach, the IDEF0 description is extended to a message passing timing diagram, similar to the manufacturing message specification MMS , to represent the communication. Also included is an example to illustrate the proposed SFCIS development procedure.

Application of manufacturing message specification for flexible manufacturing system control

This paper describes the development of the internal communication in a Flexible Manufacturing System (FMS), using Manufacturing Message Specification (MMS) and based on a Manufacturing Automation Protocol (MAP) network. Because the machines, of which the FMS consists, had few possibilities for communication with external devices, effort had to be put into making machine-specific interfaces between the NC machines and the MAP network. The interfaces were implemented by developing applications that translate MMS messages into machine-specific data and vice versa. The results of the project show that MMS can be used for the control of manufacturing machines that were not designed for use in a network for flexible manufacturing. MMS is not yet widely used. Therefore this paper is meant to demonstrate that MMS can easily be put into practice using relatively simple and off-the-shelf equipment.

The use of the Virtual Manufacturing Device in the Manufacturing Message Specification protocol for robot task control

The evolution of heterarchical control architecture for distributed manufacturing systems requires machines on the shop floor to coordinate among themselves. A flexible communication channel which can accommodate manufacturing devices of a wide variety of natures and makes is needed to handle the coordination activities. The development of the Manufacturing Message Specification (MMS) protocol is intended to fulfil this requirement. However, the standard only provides a generic model of the external behaviour of the manufacturing devices. The absence of the details of internal system structure to accomplish the external behaviour leads to implementation dependent variations which defeats the original intention of the protocol. This paper describes the use of the Virtual Manufacturing Device (VMD) for robot task control using a selected set of abstract elements from MMS. A model of the internal structure of the VMD system is presented. The model is formed with the abstract elements organised in a data structure which can be easily implemented. The working relationships of these elements are illustrated with examples. The model has successfully been applied to both hierarchical and heterarchical control architectures in three robot task control applications.

Distributed Multimedia Modeling in an MMS Context

Distributed multimedia applications would be a useful tool in the manufacturing industry. They are typically time-based applications which impose several time related constraints on communication systems. Quality of Service (QoS) parameters are necessary to describe the requirements to transfer multimedia information in communication systems. The international standard Manufacturing Message Specification (MMS) is an application layer protocol which specifies services for the distributed manufacturing applications. It enables communications between heterogeneous devices, but is not suitable for multimedia applications because it does not present QoS parameters to its objects and services. This paper proposes an extension of MMS for integrating multimedia functions. The goal is to define an MMS multimedia companion standard. Like the VMD which models manufacturing devices for MMS communication, a Virtual Communication Support (VCS) is proposed to virtualize a communication system in an MMS environment. Potential uses of VCS are also discussed.

A Distributed Real-Time Transaction Processing Environment for the CIM Applications

The paper presents a distributed transaction processing environment that permits the management and the coordination of distributed transactions for real-time Computer Integrated Manufacturing (CIM) applications. The environment has a hierarchical architecture which consists of four layers. The first layer, which represents the nucleus of this architecture is a Real-Time Operating System (RTOS). The RTOS provides the services necessary to enable the applications to meet their timing and throughput constraints. The Manufacturing Messaging Specification (MMS), supported by the ISO as an application layer standard, constitutes the second layer to support messaging communications to and from programmable devices in a CIM environment. The MMS standard introduces a complete set of services for different types of programmable devices as well as the communication protocol needed to support the transfer of data and services parameters. The third layer is composed of a Multi-Server Concept (MSC) specification which provides coordination and management levels to execute a service request by a client over an MMS object distributed over different remote servers. A Transaction Processing Facility (TPF) constitutes the fourth layer of the proposed environment. The TPF guarantees the Atomicity, Consistency, Isolation, and Durability (ACID) properties, defined by the ISO, of the distributed transactions by specifying the communications protocol and services needed to meet these properties.

112 Integrated robot control using manufacturing message specification protocol based on NetBIOS

112 Integrated robot control using manufacturing message specification protocol based on NetBIOS

An analysis of the MMS object model

MMS (Manufacturing Message Specification) is an OSI application protocol designed for the remote control and monitoring of industrial devices. In this paper, we study the MMS object model: the notion of class, naming, inheritance and structuring. We show that MMS is designed for simplicity but that some notions are not dealt with homogeneously in all classes of MMS objects. >

Protocol design and performance analysis for manufacturing message specification: A Petri net approach

The manufacturing message specification (MMS) is the ISO standard communication protocol specific to manufacturing. To analyze MMS design and performance, service unit automats are introduced to represent individual MMS services, while service connection Petri Nets (PNs) are constructed from these automats to describe MMS service connections and processes. This approach makes MMS protocol specification and analysis possible in terms of well-developed concepts and methods in PN theory. It leads to a distributed and hierarchical model of MMS software system by integrating service connection PNs. A generalized stochastic PN for MMS performance evaluation is obtained by incorporating service parameters and time factors into the model. A technique based on T-invariants is used to simplify the performance analysis.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Integrated robot control using manufacturing message specification protocol based on NetBIOS

An implementation of Manufacturing Message Specification (MMS) protocol has been made for robot control based on a token-ring personal computer (PC) network using NetBIOS. This paper discusses the construction of the MMS protocol data unit (PDU) and virtual manufacturing device (VMD) which are essential elements in the protocol. The session layer capability of the NetBIOS protocol provides a good basis for establishing the confirmed services in MMS. The services are implemented by utilising the extensive session control functions in NetBIOS and building on top the required presentation and application elements. The philosophy of multiple-access machine control in MMS is also made possible on a single-user operating system such as DOS by a ring buffer control scheme. The implication of these are further explored in relation to the dynamic control of robot over the network environment using the concepts of domain and program invocation in MMS.

Integrated Robot Control Using Manufacturing Message Specification Protocol Based on Netbios

An implementation of Manufacturing Message Specification (MMS) protocol has been made for robot control based on a token ring personal computer (PC) network using NetBIOS. The session layer stack of NetBIOS provides a good basis for developing the MMS protocol which requires extensive session control in its confirmed services. This paper discusses the construction of MMS protocol data unit (PDU) and virtual manufacturing device (VMD) which are essential elements in the protocol. Implication of these elements are explored in relation to the dynamic control of robots using the concepts of domain and program invocation.

Distributed Real-Time Systems for Manufacturing Automation

In manufacturing automation systems of distributed application processes interacting across a local area communication network are coming up with increasing importance. Standards (e.g. MAP and MMS) have been established for this kind of systems. For applications with real time constraints these standards are not fully satisfying. The paper gives some answers to key questions concerning achievable message delays and precautions to be met for getting a predictable behaviour of the whole system. Concerning aspects of the Manufacturing Message Specification (MMS) are studied in more detail.

RTMMS?An OSI-based real-time messaging system

A critical component of the MAP initiative has been the development of a message handling system—initially designed for manufacturing environments—termed MMS. In terms of the OSI model, this application-layer system is designed to support communications to and from programmable devices, specifically in manufacturing, and, more recently, in process-control environments as well. MMS also permits specific, application-oriented messaging systems to be built around the core definition of MMS—these additional systems being termed companion standards. However, although dedicated to such real-world environments, MMS does not have a direct capacity to support time-critical services. It has been recognized that such capabilities are vital in many areas of control, and therefore work needs to be undertaken to extend MMS to cover this field. This paper addresses some of the issues where MMS, in its standardized form, falls short, and suggests what can be done to overcome these difficulties. It proposes additions to the MMS profile, and basically, therefore, to the Virtual Manufacturing Device which underlies the MMS system. In the context of the paper, it should be noted that Real-time MMS is not designed as a replacement for the Manufacturing Messaging Specification, but rather functions alongside it. The paper concludes by illustrating how such real-time extensions may be implemented.