Configuration phase (for events triggered by input/output modules)

In offline mode, from the configuration editor, select Event Processing (EVT) and the event processing number for the channel of the input/output module concerned.

Unmasking phase

The task which can be interrupted must in particular:

• Enable processing of events at system level: set bit %S38 to 1 (default value).

• Unmask events with the instruction UNMASKEVT (active by default).

• Unmask the events concerned at channel level (for events triggered by input/output modules) by setting the input/output module's implicit language objects for unmasking of events to 1. By default, the events are masked.

• Check that the stack of events at system level is not saturated (bit %S39 must be at 0).

Event program creation phase

The program must:

• Determine the origin of the event(s) on the basis of the event status word associated with the input/output module if the module is able to generate several events.

• Carry out the reflex processing associated with the event. This process must be as short as possible.

• Write the reflex outputs concerned.

Note: the event status word is automatically reset to zero.