Definition:
Diagnostic Coverage Safe (DCsafe) represents how good the diagnostics are in catching safe failures. It measures the percentage of safe detected failures (automatically detected by the system’s internal diagnostics) compared to all safe failures. A device that has no diagnostics this term would be not applicable (or actually zero).
This is often used to gauge availability and uptime. Perhaps related to spurious trip rate (STR) analysis.
This can be confusing as DC is at times called DCdang. DC or DCdang is similar and represents how good the diagnostics are in catching unsafe failures.
Key Points:
- DC and DCdang are the same terms.
- DCsafe is in a way the opposite of DCdang.
Example:
A device develops a fault that causes it to fail in a safe condition, and its diagnostics automatically detect this fault while the device is still functioning (but in a safe state), that detection is counted toward DCsafe
See also: DC, safe failure fraction (SFF), Cpt
Cited Source:
- IEC 61508-2:2010, Clause 7.4.5.