FB_BA_PlantLock

The events of the objects often signal a relevant malfunction, which requires targeted switching operations to be performed on aggregates or plants. In large plants, there are often a large number of events, which then frequently have to be combined into a collective message.
To keep the programming effort for generating collective messages as low as possible, a lock priority can be determined at each event-capable object.
All four lock priorities are collected at each level of the project structure and passed up from the lowest level of the project structure to the top level.
If required, they are displayed by the instance of a function block FB_BA_PlantLock and interconnected with other function blocks for the control of plant and aggregate units.

Four lock priorities are used to differentiate the object events in order to trigger different reactions.

Local medium
Enables a local shutdown of of medium priority.
Local high
Enables a local shutdown of of higher priority.
Medium
Enables a higher-level shutdown of of medium priority.
High
Enables a higher-level shutdown of of higher priority.

Medium priority is used for technically relevant faults that affect the safety of plants. High priority can be used for faults where the safety of people is at risk.

The local faults should be used, for example, to switch off aggregates. The non-local ones should be used to shut down equipment.

The image below is intended to explain this relationship:

The effects of different lock priorities of the fault input DST are as follows:

Dst.eEnPlantLock	Cmd.bPresentVal	Cmd.eActivePrio	OpMode.AlmShutOff
LocalMedium	False	Critical	False
LocalHigh	False	Safety	False
Medium	False	Critical	Safety
High	False	Safety	Safety

Illustration

FUNCTION_BLOCK FB_BA_PlantLock
VAR_OUTPUT
  bPrioHigh           : BOOL;
  bPrioMedium         : BOOL;
  bPrioLocalHigh      : BOOL;
  bPrioLocalMedium    : BOOL;
END_VAR
VAR
  {region 'Fixed Variables'}
    iParent           : I_BA_View;
  {endregion}
END_VAR

Outputs

Name	Type	Description
bPrioLocalHigh	BOOL	The output signals a global event with a high priority.
bPrioMedium	BOOL	The output signals a global event with a medium priority.
bPrioLocalHigh	BOOL	The output signals a local event with a high priority.
bPrioLocalMedium	BOOL	The output signals a local event with a medium priority.

Requirements

Development environment	Required PLC library
TwinCAT from v3.1.4024.35	Tc3_XBA from v5.3.0.0