The DeltaV SIS function blocks are a set of blocks that run in a logic solver. You can use them to create and implement safety shutdown logic for your plant. Similar to standard control function blocks, SIS function blocks contain algorithms and parameters that customize the algorithms. A SIS function block uses parameter data which is supplied by users, by the function block itself, or by other function blocks, to perform its calculations and logic functions and to supply an output value to other function blocks or to field devices. This capability helps you implement a variety of safety related strategies, including safety shutdown sequences.
There are several categories of SIS function blocks that appear in palettes in Control Studio:
Certain SIS function blocks require logic solvers of a specific revision. Module properties dialogs enable you to specify the revision of the target logic solver. In addition, logic solver properties dialogs enable you to specify the revision of the logic solver. When you create a module, make sure the target logic solver can support the function blocks in the module. Also, make sure the logic solver properties dialog specifies the correct revision.
The Guide to SIS Function Blocks topic includes revision information.