This is a one-shot write trigger, with only the value state-to-active defined, that forces the card's reported diagnostic state back from marginal to active and clears the yellow status LED to green. This is explicitly a manual override rather than a fix: it clears the visual and SNMP alarm without addressing whatever background diagnostic issue caused the marginal flag in the first place, so an admin who sets this without also resolving the underlying fault risks masking a real hardware problem. For example, after physically re-seating a card whose loose connector caused a transient marginal flag, the admin sets cardDiagLEDReset to clear the yellow LED once they've confirmed the seating fixed the actual cause.