This function block is used to finish a sequence control. It is a special form of the Step function block.

A token that comes to a Stop block cannot be transferred to another block. Only by a preset the Stop block can lose a token at runtime. With the Preset function block the flow control is set to a predefined state and so a token will be detracted from every step, including a Stop block.

The function block has the input SI and the output SM. The output SM is a BIT data type. It shows if this block has a token or not. SI has to be connected with a transition. Over this transition the token will be transferred to this block.

For general information about sequence function and its realization see introduction.


Name I/O Type(s) Function
SI I TOSTEP Sequence input
SM O BIT State (token)


If this function block is currently active, the symbol will be depicted in green.


All flow controls within a structure block are part of the same flow control net. A macro block can be a part of a flow control. For connecting a macro with a flow control block, use the connectors of type TOTRANS or TOSTEP.