The Stored Delayed qualifier starts a timer when the step activates and latches the output to TRUE after the delay, even if the step has already deactivated.
Unlike the plain D qualifier, the SD timer is not cancelled when the step deactivates. Once the step has activated, the delayed latch is guaranteed to happen.
{GIF:HERE} - Step properties panel showing the action 'Delayed alarm' with qualifier dropdown set to 'SD' (Stored Delayed) and duration field set to 10000 ms
from automation_machine import ActionQualifier
step.add_action("delayed_alarm", "Delayed alarm", qualifier=ActionQualifier.SD, duration=10000)
The duration parameter is required and specifies the delay in milliseconds. Use R in a later step to reset the output.