Actions and Recommendations from the nanoFIP FMC Dependability Analysis
A = proposed Action; R = Recommendation TBD ; see also full report
To be checked if completed or strikethrough if obsolete
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[R] Use of a faster triggering fuse than FEASTMP / bPOL DC/DC converter OCP on radtol system board to prevent short circuits of the nanoFIP FMC from affecting the radtol system board. In addition, faster triggering than RaToPUS OCP to prevent from bringing the DI/OT crate down. -
[R, optional] Use of ‘DRB’ packages for the linear voltage regulators to further optimise the heat dissipation. -
[R] Implementation of a Front End Computer (FEC) check to identify a potential lost fieldbus communication and/or lost node, e.g. from a wrong DIP switches configuration. Additional application specific mitigation (e.g. fail-safe) to be implemented upon detection. -
[R] Performance of a bus/node identification test on installation and after replacement to declare the bus segment as operational. -> user manual Note: A wrong DIP switches configuration can affect up to two DI/OT crates. -
[R] Implementation of a check performed by the radtol system board to verify the communication with the nanoFIP FMC, e.g. to write to a nanoFIP register, read back, and compare. Potential failure modes: ‘FMC data line/pin open’ -
[A] Tests at top performance parameters for functional validation of the nanoFIP FMC. -
[A] Validation tests at determined environmental stress limits (see here) and top performance. -
[A] High stress tests to determine the robustness and sufficient margin for both functional errors and hardware failures against different stresses (see here). -
[A] High quality requirements during the PCB and PCBA production process (IPC class 3), supported by a high level of inspections. Final End of Line functional test bench (“PTS”), as well as potentially intermediate component test benches to be designed and used. -
[R] Special attention to be paid during the assembly process of the DIP switches as well as during the subsequent functional testing and screening campaign. -
[A] Screening (temperature cycling) and reliability testing (run in) as outlined here. -
[R] Comprehensive failure monitoring, root-cause analysis and failure data analysis (Weibull analysis) for all units installed.