Symbol: 
Function: This command inserts a step and a transition before the selected point.
Call: Main menu “SFC”
If you have selected a step, then CODESYS inserts a new step-transition combination. If you have selected a transition, then a new transition-step combination is inserted.
The new step is named Step<n> by default, where n is an incremental number beginning at 0 for the first step that was inserted in addition to the initial step. The new transition
is named Trans<n> by default. You can edit the default names directly by clicking the names.