The scheduler object cannot directly generate alarms when, e.g., a commanded object cannot be found.
The alarm function (extended, basic or simple) which defines the alarm behavior of the object in the system, and the alarm class do not exist because of standard compliance.
The fault alarming of the schedule object must therefore be implemented as an additional binary value function block. That's why the function block is linked with the Dstb (Disturbed) pin of the scheduler and parameterized accordingly. The additional binary value function block is optional and only required, when a fault alarming of the scheduler is wanted, e.g., for scheduling external objects.