User access and security at runtime

Operators with the appropriate permissions can change the PlantState of an area through a runtime client. An operator may have to change PlantState from Startup to Running, for example. Scripts can also be used to implement modifications.

To change a PlantState, the operator enters a string to match one of the defined PlantState values (for example, "Running"). Before a change to PlantState can be implemented, the system checks that the user belongs to a role that has the permission "Can Modify Plant State of an Area" and is therefore authorized to make the change. If the operator enters a string that does not match a defined PlantState, the change is rejected.

At runtime, the AlarmMode attribute is read-only. Therefore, the AlarmMode for a PlantState cannot be changed through a runtime client (for example, changing from enable to silence). It can only be changed through the IDE.

If an area is assigned to a PlantState and the PlantState is deleted through the IDE, the area will remain in that PlantState until it is changed. If AlarmMode for the deleted PlantState is anything other than enable, the AlarmMode will change to enable.

Note: Operators with appropriate permissions can use the AlarmModeCmd attribute to change AlarmMode of an area at runtime. However, the AlarmModeCmd can only be used to set a more restrictive condition than the AlarmMode of the area’s corresponding PlantState. For more information about changing alarm modes, see Enable, silence, and disable alarms.