DuplicaTTor® Design Suite (DDS-0405)
The DuplicaTTor® Design Suite 0405 (DDS-0405) is aimed primarily at organisations that wish to develop TT systems in compliance with IEC 61508 (up to ‘SIL 3’) and / or ISO 13849 (up to Pl e Cat 4).
DDS-0405 targets the DuplicaTTor Evaluation Board (DEB-0405).
The DDS-0405 is accompanied by a comprehensive suite of documentation, including a detailed safety manual.
DDS-0405 will be released in December 2017.
We provide further information about this forthcoming product on this page.[This page was lasted updated: 2017-10-19]
The DDS-0405 ‘Example Configuration’
The DDS-0405 suite is based around an ‘example configuration’ (the ‘DDS-0405-EC’).
This comprehensive code library illustrates how to create a complete ‘fail safe’ TT design.
A full ‘Software Requirements Specification’ (SoRS) is provided with the DDS-0405-EC.
By developing their own software based on the DDS-0405-EC foundation (and adapting the SoRS to match), development teams will be able to bring safety-related products (that are compliant, where required, with standards such as IEC 61508 and / or ISO 13849) to market very quickly.
An overview of the DDS-0405-EC is provided in the figure below.
Related hardware platform
The DDS-0405-EC targets the DEB-0405 evaluation board.
Achieving ‘Hardware Fault Tolerance’ in compliance with IEC 61508
International safety standard IEC 61508 is concerned with functional safety, achieved by means of systems that are primarily implemented in electrical and/or electronic and/or programmable electronic technologies (for example, using microcontrollers and appropriate software).
Hardware Fault Tolerance (HFT) is a key consideration in many IEC 61508 designs.
- When we have an HFT of 0, this means that we have only a single processing path available: if this fails, it may be challenging to: [i] detect this failure; and [ii] ensure that the system can enter an appropriate ‘Fail-Safe State’;
- When we have an HFT of 1, this means that we have a second (independent) processing path available: if one processing path fails, the second processing path is intended to be able to detect this and act appropriately.
A design with HFT of 1 is often required in order to produce a ‘SIL 3’ design in compliance with IEC 61508.
As an example, the figure below illustrates an example of a design with HFT of 1 that could be implemented very simply and effectively using the DuplicaTTor® Design Suite 0405.
Implementing ‘Designated Architectures’ in compliance with ISO 13849
ISO 13849 applies to the development of control systems for a very wide range of machinery.
More specifically, ISO 13849-1 provides safety requirements and guidance on the principles for the design and integration of safety-related parts of control systems (SRP/CS), including the design of software.
ISO 13849-1 provides specific requirements for SRP/CS using programmable electronic system(s).
ISO 13849-1 includes a set of 5 ‘designated architectures’ (DAs): using one of these DAs may help to make it easier to demonstrate compliance with the standard. As an example, the figure below represents a Category 4 designated architecture.
The figure below illustrates an outline design for an ‘Operator in Place’ system that is used to control a piece of machinery. This design implements a ‘Category 4’ designated architecture.
This design employs two low-cost cameras and a ‘DuplicaTTor-B’ software platform to ensure that the machine can only move if there is an alert operator in the cab.
Such a system design can be explored very simply and effectively using the DuplicaTTor® Design Suite 0405.
What’s in the box?
The DuplicaTTor Design Suite 0405 includes the following:
- A User Guide.
- The DDS-0405 ‘Example Configuration’ (DDS-0405-EC).
- A ‘Software Requirements Specification’ (SoRS) matched to the DDS-0405-EC.
- A Safety Manual.
- A code configuration supporting measurement of task execution times.
- A code configuration supporting the generation of Tick Lists.
- A ReliabiliTTy Technology Licence.
Further information will be available shortly.
DDS-0405 packages all include the comprehensive DDS-0405 safety manual.
When used in compliance with this safety manual, the DDS-0405 software framework can provide a highly-effective foundation for developing robust and reliable products, in compliance with IEC 61508 (up to SIL 3) and / or ISO 13849 (up to Pl e Cat 4).
The structure of the safety manual is presented below (Draft 2017-10-19).
ReliabiliTTy Technology Licence
PART ONE: Introduction
1. Overview of this safety manual
2. How to adapt the DDS-0405-EC to match your system requirements
PART TWO: Design assumptions and outline design examples
3. An overview of the example configuration
4. IMPORTANT: Key design assumption
5. Example: Meeting IEC 61508 requirements
6. Example: Meeting ISO 13849 requirements
PART THREE: How to adapt the DDS-I-0405 EC
7. How to adapt and use the DDS-I-0405-EC
8. Competence level required
9. Steps required to port the DDS-I-0405 software
10. Compiler requirements
11. Other software needed for safety-related designs
12. How to create the Tasks
PART FOUR: Providing evidence of compliance with system requirements
13. General comments
14. Determining the Slave delay
15. Determining the Slave jitter
16. Determining the maximum CPU load
17. Determining system response times
18. Determining the Task release jitter
APPENDIX 1: Task execution-time measurements
APPENDIX 2: Tick Lists
How to order your DDS-0405
DDS-0405 will be released in December 2017.
Please contact us for further information.