EN 61499

from Wikipedia, the free encyclopedia
Logo of the German Institute for Standardization DIN EN 61499
Area Function blocks for distributed control systems
title Function modules
Latest edition Part 1: 11.2012 Edition 2.0

Part 2: 11.2012 Edition 2.0

Part 3: 2004 Edition 1, withdrawn in 2008

Part 4: 01.2013 Edition 2.0

ISO IEC 61499

The European standard EN 61499 and international standard IEC 61499 deal with function blocks for industrial process measurement and control systems. It is also valid as a DIN standard for Germany and was first published in 2005. The specification IEC 61499 or EN 61499 defines a generic model for distributed control systems and is based on IEC 61131 or EN 61131 . In addition to the standard itself, the concepts of the IEC-61499 standard are detailed in the books by Lewis and Zoitl and Vyatkin.

Part 1: architecture

In the 1st part of IEC 61499 the architecture for distributed systems is defined. The cyclical execution model of IEC 61131 is replaced in IEC 61499 by an event-oriented execution model, which enables an explicit definition of the execution sequence of function blocks. The event function blocks defined in Part 1 Appendix A, especially the E_CYCLE function block for generating events, also allow the implementation of periodically executed applications.

The IEC 61499 uses an application-centered design. An application is created for the entire system and then distributed to the existing devices in the system. The devices of a system are described in a device model, with the topology of the system being reflected in the system model. The current distribution of an application is recorded in the distribution model. Applications of the system are therefore managed jointly, but can be distributed.

IEC 61499 application and device model

Applications are defined by a function block network. IEC 61499 function blocks are based on IEC 61131-3 function blocks. Therefore they also have an interface and a function implementation or description. In contrast to IEC 61131-3, IEC 61499 interfaces have, in addition to the data inputs and outputs, event inputs and outputs that can be connected to data inputs and outputs via a so-called WITH relationship. The IEC 61499 defines different block types, each of which can contain a description of behavior in the form of service sequences :

Interface of an IEC 61499 function block
  • Service interface function block (SIFB): The source code is hidden and its function is only described using service sequences .
  • Basic function block (BFB): Its function is described in the form of an Execution Control Chart (ECC), similar to a UML state transition diagram . Several actions can be assigned to each state, each of which is assigned one or no algorithm and one or no output event. Algorithms can be implemented according to any consistent standard.
  • Composite function block (CFB): Its function is described in the form of a function block network .
  • Adapter interface type (adapter interfaces): An adapter interface is not a real function module, it bundles several event and data connections in one connection and offers an interface concept for decoupling specification and implementation.
  • Subapplication: Your function is also described in the form of a function block network . In contrast to CFBs, sub-applications are distributable.

To manage the applications within a device, IEC 61499 defines a management model. The device manager manages the life cycle of the resources and takes over the communication with software tools (e.g. configuration tool or agent ). This communication takes place through management commands. The software tool interface and the management commands allow online reconfiguration of applications, as Zoitl was able to show.

Part 2: Requirements for software tools

The 2nd part of IEC 61499 describes the requirements for IEC-61499-compliant software tools. This concerns the representation and portability of IEC-61499 elements including a document type definition format for exchanging IEC-61499 elements between different software tools.

Some IEC-61499-compliant software tools are already available. These include commercial software tools, open source software tools, but also academic developments and research developments. Usually, an IEC-61499-compliant runtime environment and an IEC-61499-compliant development environment are required.

Part 3: Tutorial Information (withdrawn in 2008)

The 3rd part of IEC 61499, withdrawn in 2008, relates to the 1st edition of the standard and answers FAQs related to IEC 61499. In addition, the use of the elements of IEC 61499 to solve common problems in the development of automation systems is illustrated using examples described.

The examples relate, among other things, to the use of SIFBs such as communication function blocks for remote access to real-time data and parameters of function blocks, the use of adapter interfaces for implementing object-oriented concepts, initialization algorithms in function block networks, the implementation of an ECC for a simplified motor control of a hypothetical video recorder .

In addition, the effects of mapping with regard to the handling of communication function blocks are discussed, as well as device management with the help of management applications and their function blocks, such as the functionality of the Device Manager function block (DEV_MGR).

Part 4: Rules for standard-compliant profiles (compliance profiles)

The 4th part of IEC 61499 describes rules that a system, device or software tool must support in order to be considered IEC 61499 compliant. These rules relate to interoperability, portability, and configurability. Two devices are interoperable if they can work together in order to be able to perform the functions defined in a system configuration together. IEC 61499-compliant applications must be portable, i.e. they must be able to be exchanged between software tools from different manufacturers, taking into account the requirements for software tools specified in IEC 61499-2. It must be possible to configure devices from different manufacturers using software tools from different manufacturers.

In addition to these general rules, Part 4 also defines the structure of so-called compliance profiles . A compliance profile describes how a system fulfills the rules of the IEC 61499 standard. The configurability of a device by a software tool is z. B. determined by the supported management commands, whereby each conforming device must support the commands create, delete, start, stop, kill, query, read, write, reset , so that IEC 61499 applications can be loaded and executed on it. The exchange format, which determines the portability of IEC 61499 compliant applications, is defined in part 2 and in the compliance profile z. B. supplemented by supported file extensions for library elements.

The interoperability between devices from different manufacturers is defined via the different layers of the OSI model . The supported function blocks for communication between the devices must be taken into account, such as PUBLISH/SUBSCRIBEand CLIENT/SERVERand their status outputs, IP addresses and port numbers as well as the data encoding.

HOLOBLOC, Inc. defines the “IEC 61499 compliance profile for feasibility demonstrations”, which is supported, for example, by the IEC 61499 compliant software tools FBDK, 4diac IDE and nxtSTUDIO.

Individual evidence

  1. ↑ Alois Zoitl and Robert Lewis: Modeling control systems using IEC 61,499th 2nd Edition , Control Engineering Series 95, The Institution of Electrical Engineers, London July, 2014.
  2. ↑ Valeriy Vyatkin: IEC 61499 Function Blocks for Embedded and Distributed Control Systems Design, Instrumentation Society of America, USA, 2006, 2011 (second edition), 2014 (third edition in German and English)
  3. ↑ Alois Zoitl Real-Time Execution for IEC 61499, Instrumentation Society of America (ISA), USA, ISBN 1934394270 , ISBN 978-1934394274 , November, 2008.
  4. ↑ IEC 61499 The New Standard in Automation: Tools. Retrieved October 12, 2015 .
  5. ↑ IEC 61499 Compliance Profile for Feasibility Demonstrations. Retrieved October 12, 2015 .
  6. ↑ FBDK - The Function Block Development Kit. Retrieved October 12, 2015 .
  7. ↑ Eclipse 4diac - Open source IEC 61499 environment. Retrieved October 12, 2015 .
  8. ↑ nxtControl - IEC 61499 compliant automation system. Retrieved July 20, 2017 .

literature