In case of flasher failure, an unacknowledged alarm should assume a highly conspicuous state such as a steady on (e.g., illuminated) state rather than a less conspicuous state such as off.
Additional Information:
While it is preferable in the case of a flasher failure for the associated alarm element to remain on (e.g., illuminated) rather than off, a unique and highly conspicuous code is best. The code should be unique to prevent confusion between unacknowledged and acknowledged alarms. It should be salient to alert the operator to the malfunction of the alarm display system. In addition, other alerting mechanisms such as warning messages may be used to inform the operator of a malfunction in the alarm display system.