BISv2 Reliability Study Progress Meeting - CIBAB

Present: M. Blaszkiewicz, A. Collinet, L. Felsberger, T. Podzorny, I. Romera Ramirez  

Minutes

The presentation showed general statistics from the failure rate prediction step, proposed end-effects definitions, top contributors to the overall failure rate and remaining questions to conclude. 

In the discussion, the following points were made:

• Remaining 49 capacitors are probably filters where the nets can not easily be read out.
• There are 3 beam permit output channels because of different actuators:
  • E.g. in SPS Injection there is a need for more than one channel.
  • In the LHC, it will be only one channel used.
  • In the FMECA table, the effects will be filled for all, but in the global model only a single connection should be considered.
• End-effects definitions to be updated:
  • maintenance - no immediate action
  • false dump - can also be availability problem
• Adjustments to components' failure rate predition:
  • Transistors
    • FITS are probably from powering transitors rather than ones used in the CIBAB context.
  • TVS
    • Various parameters specified in the datasheets (clamping/standing)
    • Parameters in the 217Plus don't make sense in this case (operating and rated voltage)
    • These ones are used for RS485; however, operating voltage could be higher as sometimes it may be an aggregation of other voltages.
• Designators naming conventions
  • The problems are coming from default way Altium replicated channels; mostly for LEDs pages
  • FPGA - there is only one component but referred to using different letters in the end.
    • This results in the similar desingator names as for different channels. 
    • There is no straight-forward way to establish if one or the other is the case for specific designator name.
• Channel configurations
  • If disabled by accident, they send fail safe value.

Next steps

1. Share the FMECA table with Antoine.
2. Follow-up the failure rate prediction of transistors and TVS diodes in 217Plus standard.