Mms: A Communication Language for Manufacturing

ISBN-13: 9783540590613 / Angielski / Miękka / 1995 / 185 str.

Consortium Cce-Cnma

Opis

Today's manufacturing environment is characterised by significant change in the way it is able to respond to its business objectives. Companies now face new challenges to meet customer demands including greater flexibility, a wider range of products, higher quality, improved lead time, whilst maintaining _c.ompetitive prices. The changes manifest in each company will differ but, the trend is towards providing a leaner, more responsive organisation. This is reflected in the need for Information Technology (IT) systems to be more integrated across an enterprise and for the systems to be provided on a distributed basis. At the same time it is imperative that the costs associated with these IT systems and the range of skills required by an enterprise to develop and support such systems should be minimal. One way of achieving this objective is to adopt the use of standards. During recent years there has been a lot of activity to standardise the way that manufacturing devices communicate with each other. Considerable progress has been made, thanks not least to the success of the international effort of stand ardisation bodies like ISO, IEEE and IEC, and projects applying standardised protocols like Manufacturing Automation Protocol (MAP), in the USA, Commun ications Network for Manufacturing Applications (CNMA) in Europe and not forgetting Mini-MAP and Fieldbus technology."

Spis treści

1. Introduction.- 1.1 The need for standards.- 1.2 Motivation for the book.- 1.3 Purpose of the book.- 1.4 Organisation of the book.- 1.5 Acknowledgements.- 2. Rationale and Context.- 2.1 Rationale for MMS.- 2.2 The OSI reference model.- 2.3 MAP and CNMA.- 2.4 Mini-MAP.- 2.5 Profibus.- 2.6 Summary.- 3. Manufacturing Message Specification (MMS).- 3.1 Basics.- 3.2 The MMS object model.- 3.3 Confirmed and unconfirmed services.- 3.3.1 Confirmed services.- 3.3.2 Unconfirmed services.- 3.4 The MMS-related standards.- 3.5 Summary.- 4. MMS Core Object Classes.- 4.1 Virtual Manufacturing Device (VMD).- 4.1.1 Attributes of the VMD.- 4.1.2 A simple example.- 4.1.3 The UnsolicitedStatus service.- 4.1.4 Other attributes.- 4.1.5 Naming in MMS.- 4.1.6 Associations and the MMS environment.- 4.2 Domains.- 4.2.1 Attributes of the domain object.- 4.2.2 Domain download initiated by the client.- 4.2.3 Domain download initiated by the server.- 4.2.4 Domain upload.- 4.2.5 Deletion of a domain.- 4.2.6 Getting the attributes of a domain.- 4.2.7 Practical example.- 4.3 Program invocations.- 4.3.1 Attributes of a program invocation.- 4.3.2 Creation of a program invocation.- 4.3.3 Starting a PI.- 4.3.4 Obtaining the state of a PI.- 4.3.5 Deletion of a PI.- 4.4 MMS variables.- 4.4.1 Attributes of a named variable.- 4.4.2 Data types.- 4.4.3 Alternate access.- 4.4.4 Getting the attributes of a variable.- 4.4.5 Reading variables.- 4.4.6 Writing variables.- 4.5 Summary.- 5. MMS in Real Manufacturing Devices.- 5.1 Introduction.- 5.2 The Siemens MMS implementation for SIMATIC PLCs.- 5.2.1 VMD related services.- 5.2.2 Accessing variables in the PLC.- 5.2.3 Managing domains in the PLC.- 5.2.4 Managing programs on the PLC.- 5.3 The Siemens MMS implementation for SINUMERIK NCs.- 5.3.1 Structure of the NC.- 5.3.2 Accessing variables.- 5.3.3 Managing domains.- 5.3.4 Controlling programs.- 5.3.5 Alarms.- 5.4 The Télémécanique MMS implementation for TSX 47 PLCS.- 5.4.1 VMD related services.- 5.4.2 Accessing variables in the PLC.- 5.4.3 Managing domains in the PLC.- 5.4.4 Managing programs on the PLC.- 5.5 Comparison of the two PLC MMS implementations.- 5.6 Summary.- 6. Use of MMS in a Real Manufacturing Application.- 6.1 Overview.- 6.2 Rail guided vehicle (RGV).- 6.2.1 RGV state diagram.- 6.2.2 Transportation of a pallet from a clamping station to the pallet store.- 6.2.3 Transportation of a pallet from the pallet store to a machining centre.- 6.2.4 Mapping to MMS objects.- 6.2.5 MMS services offered by the RGV.- 6.3 Machining centre.- 6.3.1 Overview of the information flow.- 6.3.2 Mapping to MMS objects and services.- 6.3.3 NC-CS models used in the example manufacturing facility.- 6.3.4 NC system state model.- 6.3.5 NC device control model.- 6.3.6 Alarm model.- 6.3.7 NC data store model.- 6.3.8 Tool management.- 6.3.9 NC program management.- 6.3.10 Tool data transfer.- 6.4 Summary.- 7. MMSI.- 7.1 Introduction.- 7.2 The main benefits of a standard API.- 7.3 Purpose and scope of MMSI.- 7.4 Properties of MMSI.- 7.5 Classes of MMSI functions.- 7.6 Naming rules for MMSI functions.- 7.7 Context-sensitive functions.- 7.8 Support functions.- 7.9 Context-free functions.- 7.10 Parameters of MMSI functions.- 7.10.1 Exposed parameters.- 7.10.2 DCB parameters.- 7.10.3 Handles.- 7.10.4 Parameter order.- 7.10.5 Return code.- 7.11 Synchronous and asynchronous modes.- 7.11.1 Return event.- 7.11.2 Synchronous call.- 7.11.3 Asynchronous call.- 7.11.4 Example.- 7.12 DCB management.- 7.12.1 DCB types.- 7.12.2 DCB allocation and deallocation.- 7.12.3 Using the Input DCB.- 7.12.4 Using Inout DCBs.- 7.13 MMSI main data types.- 7.13.1 Basic data types.- 7.13.2 Data types of exposed parameters.- 7.13.3 DCB Component data types.- 7.14 MMSI objects and handles.- 7.14.1 Concept of handle.- 7.14.2 Handles and context-free functions.- 7.14.3 Creating a new handle.- 7.14.4 Making a list of handles.- 7.14.5 Extracting a handle or an object from a list.- 7.14.6 Duplicating a handle.- 7.14.7 Freeing a handle.- 7.15 Reading a variable.- 7.16 Summary.- 8. A DDE Interface to MMS.- 8.1 Introduction.- 8.2 Windows DDE basics.- 8.2.1 Client server principle.- 8.2.2 DDE conversation.- 8.2.3 The parameters application, topic and item.- 8.2.4 DDE messages.- 8.2.5 A typical DDE conversation.- 8.2.6 Cold link between client and server.- 8.2.7 Hot link between client and server.- 8.2.8 Warm link between client and server.- 8.2.9 DDE application interface.- 8.3 The MMS/DDE application interface.- 8.3.1 Overview.- 8.3.2 Establishing connections to MMS via the DDE parameter topic.- 8.3.3 Terminating a DDE conversation.- 8.3.4 Status.- 8.3.5 UnsolicitedStatus.- 8.3.6 MMS variable services.- 8.3.6.1 Variable types.- 8.3.6.2 Syntax of variable values.- 8.3.6.3 Access and alternate access.- 8.3.6.4 Reading a variable.- 8.3.6.5 Writing a variable.- 8.3.6.6 Notification of variable value changes (Information Report).- 8.3.7 MMS domain download.- 8.3.8 Further MMS services supported.- 8.4 Operation of the MMS/DDE server.- 8.4.1 Introduction.- 8.4.2 Initiating a DDE conversation.- 8.4.3 Terminating a DDE conversation.- 8.4.4 Status.- 8.4.5 UnsolicitedStatus.- 8.4.6 MMS variable services.- 8.4.6.1 Reading the value of a variable on a cold link.- 8.4.6.2 Reading the value of a variable via hotlink (Information Report).- 8.4.6.3 Reading the value of a variable via hotlink (Polling).- 8.4.6.4 Writing the value of a variable.- 8.4.7 Downloading a domain.- 8.5 Example: calling MMS in an Excel spreadsheet.- 8.6 Summary.- 9. Other MMS Objects and Services.- 9.1 Operator stations.- 9.2 Semaphores.- 9.3 Events.- 9.4 Journals.- 9.5 Summary.- 10. Conclusion.- 10.1 What has been discussed.- 10.2 Why is MMS important?.- 10.3 Where is MMS being applied?.- 10.4 What is MMS used for?.- 10.5 What are the main benefits of using MMS?.- 10.6 What about interoperability?.- 10.7 Where can I obtain more information?.- 10.8 So, what of the future?.- Glossary of Terms.- Appendix 1. The MMS and CNMA Information Servers.- Appendix 2. MMSI Context Sensitive Functions.