data connections within one connection and provides an interface concept to separate specification and implementation. Subapplication: Its functionality is also defined as a function block network. In contrast to CFBs, subapplications can be distributed. To maintain the applications on a device IEC 61499 provides a management model. The device manager maintains the lifecycle of any resource and manages the communication with the software tools (e.g., configuration tool, agent) via management commands. Through the interface of the software tool and the management commands, online reconfiguration of IEC 61499 applications can be realized. Part 2: Software tool requirements IEC 61499-2 defines requirements for software tools to be compliant to IEC 61499. This includes requirements for the representation and the portability of IEC 61499 elements as well as a DTD format to exchange IEC 61499 elements between different software tools. There are already some IEC 61499 compliant software tools available. Among these are commercial software tools, open-source software tools, and academic and research developments. Usually an IEC 61499 compliant runtime environment and an IEC 61499 compliant development environment is needed. Part 3: Tutorial Information (2008 withdrawn) IEC 61499-3 was related to an early Publicly Available Specification (PAS) version of the standard and was withdrawn in 2008. This part answered FAQs related to the IEC 61499 standard and described the use of IEC 61499 elements with examples to solve common challenges during the engineering of automation systems. Among other examples, IEC 61499-3 described the use of SIFBs as communication function blocks for remote access to real-time data and parameters of function blocks; the use of adapter interfaces to implement object oriented concepts; initialization algorithms in function block networks; and the implementation of ECCs for a simplified motor control of hypothetical VCRs. Additionally the impacts of the mapping concerning the communication function blocks was explained, as well as the device management by management applications and its function blocks, and the principle of the device manager function block (DEV_MGR). Part 4: Rules for compliance profiles IEC 61499-4 describes the rules that a system, device or software tool must follow to be compliant to IEC 61499. These rules are related to interoperability, portability and configuration. Two devices are interoperable if they can work together to provide the functionality specified by a system configuration. Applications compliant to IEC 61499 have to be portable, which means that they can be exchanged between software tools of different vendors considering the