TC5 - Safety - introduction
PLCopen, together with its members and external safety related organizations, defined safety related aspects within the IEC 61131-3 development environments. With this, the safety aspects can be supported by a dedicated software tool, which is integrated into the software development tools. As such it combines the logic and motion application development with the related safety aspects. This combination helps developers to integrate safety related functionality into their systems, even from the beginning of the development cycle, while contributing to the understanding of safety aspects.
Basic requirementsThe basic requirements for safety application for the machine builders are independent from the applicable safety standards:
Standardization the way outFor users, these high demanding requirements should be controlled and reduced. This can be done via standardized solutions with which the normal functionalities can be easily implemented. Standardization in functionality and the integration and support from the software tools helps the programmers to integrate safety in their applications from the beginning, without inhibiting their functionality and performance, and without adding costs. This was exactly the target of the PLCopen Technical Committee 5 Safety. With support from nearly all relevant safety control suppliers, software suppliers, and safety related organizations, they produced the first specification. Included in this specification is:
Overview of the applicable Function Blocks
User BenefitsThis complete approach provides the user with a harmonized view to the total application, safety and non-safety related application software within one environment. And with multiple implementations, this is also valid across platforms.
This means less educational efforts, and simpler transfer of knowledge and application software between different controls. Also, it tackles the not-invented-here syndrome, which often is a cause of errors and additional costs. By using tested functionality, and support in the programming environment, including language definition with subsets of functionality, one is able to create safety related application programs for easy commissioning.
|Part 1 - Concepts and Functions Blocks - is focused to the implementers of the safety functionalities. With this part 1 the safety aspects can be transferred to a software tool, which is integrated in the software development.|
|Part 2 - User Guidelines - is focused to the users of the PLCopen functionalities and demonstrates the ease of use of the defined function blocks in real life applications.|
|Part 3 - Extensions to the Function Blocks - extends the scope of the specification and harmonizes the diagnostics interface for easier handling by the user.|
|Part 4 - Application specific FBs for Presses - contains a general overview of the implementation of safety around presses.|
BGIA, the German certification institute for research and testing reviewed the PLCopen specification Part 1 and confirmed that it meets the relevant aspects of IEC 61508 and the related standards and can be used as a part of a specific safety requirement specification.
The German test & certification organization DGUV approved the PLCopen Specifications Part 3 and Part 4 as suitable basis to develop function blocks for safety applications for presses. As such the DGUV recommends that for safety applications for presses the function blocks are developed according to the PLCopen document and that their functionality is tested on a press.