Functional Safety
Reliability Data (MTTF)
for PLUS+1 Microcontrollers and I/O modules
www.danfoss.com
Functional Safety
Reliability data (MTTF) for MC and I/O modules
Revision history |
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February 2020 |
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Component and calculation summary chapter/topic MC050-010 added |
0304 |
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January 2020 |
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Corrections made in Component and calculation summary |
0303 |
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December 2019 |
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Component and calculation summary chapter/topic MC050-110 and MC050-118 replaced |
0201 |
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MC050-110; Added row to Device total table with MC050-118 information |
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July 2016 |
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First edition |
0101 |
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2 | © Danfoss | February 2020 |
AB202286484713en-000304 |
Functional Safety |
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Reliability data (MTTF) for MC and I/O modules |
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Contents |
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Overview |
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Reliability Data (MTTF).................................................................................................................................................................... |
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Standards and references |
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Introduction........................................................................................................................................................................................ |
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Assumptions....................................................................................................................................................................................... |
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Standards............................................................................................................................................................................................. |
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Calculations........................................................................................................................................................................................ |
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Component and calculation summary |
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MC012-110 and IOX012-110........................................................................................................................................................ |
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MC024-110.......................................................................................................................................................................................... |
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MC024-120 and IOX024-120........................................................................................................................................................ |
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MC024-130.......................................................................................................................................................................................... |
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MC050-010.......................................................................................................................................................................................... |
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MC050-110 and MC050-118......................................................................................................................................................... |
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MC050-120....................................................................................................................................................................................... |
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MC050-155....................................................................................................................................................................................... |
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OX012-110........................................................................................................................................................................................ |
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OX024-110........................................................................................................................................................................................ |
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Terms and definitions |
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PFH and FIT....................................................................................................................................................................................... |
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© Danfoss | February 2020 |
AB202286484713en-000304 | 3 |
Functional Safety
Reliability data (MTTF) for MC and I/O modules
Transfer of Mean Time to Failure (MTTF) data for the given product from Danfoss to the appropriate party.
This Mean Time to Failure (MTTF) data has been compiled by the Business Area engineering team responsible. These are professionals at Danfoss, who have the authority and technical knowledge to calculate the MTTF Data for this product based on the standards set in place by both the industry and/or Danfoss.
The purpose of this document is to assist in the transfer of MTTF data for the given product from Danfoss to the appropriate party in a way which will result in a clear understanding and documentation on how we derived it.
This MTTF data is provided to assist in calculating the overall MTTF of a complete or partially complete piece of machinery. Danfoss cannot be held responsible for the suitability of these calculated MTTF values for use in the calculation of the overall machinery MTTF values.
The MTTF values are based on a specific machine use, operating environment, and/or duty cycle as stated by the standards set in place by both the industry and/or Danfoss.
This communication along with any attached Danfoss drawings, sketches, or data is transmitted in confidence. No information stated in this document or any attachments or supplements may be reproduced or disclosed in whole or in part without written permission of Danfoss. Further, neither these documents nor any attachments are a warranty of any sort by Danfoss or a guarantee of machine suitability for its intended purpose. It remains the responsibility of the machine manufacturer to ensure overall machine functionality and overall machine safety.
4 | © Danfoss | February 2020 |
AB202286484713en-000304 |
Functional Safety
Reliability data (MTTF) for MC and I/O modules
As of December 29, 2009, Machinery Directive 2006/42/EC is effective for all machinery placed on the market in the European community. This directive mandates that machinery manufacturers are responsible for performing and documenting a Hazard and Risk Assessment. Each identified risk must then be addressed to ensure risk reduction to an acceptable risk level.
The processes to guide the execution of these activities are defined in various harmonized standards such as:
•ISO 12100:2010 Safety of Machinery
‒General principles for design
‒Risk assessment and risk reduction
•ISO 13849 Safety of Machinery
‒Safety-related parts of control systems
Danfoss adds value by participating in the machine manufacturers process and providing the appropriate product information to enable the required probabilistic calculations.
The failure rate listed in this document is the result of a FMEDA analysis.
All failure rates were calculated using component data from MIL-HDBK-217F at 45°C, unless otherwise noted. All failure mode distributions were taken from IEC 62061:2005 Annex D.
For inputs, a failure included in MTTFd and PFH is categorized as a mismatch between expected and measured signal.
For logic and outputs, failure included in MTTFd and PFH is categorized as one that causes:
•Loss of high-side switch turn-off capability
•Uncommanded turn-on of high-side switch
•A mismatch between commanded and actual current (for proportional outputs only)
Analysis should be performed, taking into account if not all components fail dangerously.
IEC 61508:2006 |
PLUS+1® microcontroller hardware category - Type B device |
IEC 62061:2005 Annex D |
Failure modes and percentages |
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MIL-HDBK-217F |
Reliability prediction of electronic equipment |
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Probability does not consider CAN communication external issues.
© Danfoss | February 2020 |
AB202286484713en-000304 | 5 |