Basic sequence elements (steps, links, and transitions)

Each step represents one use of an

Equipment Phase

to perform an action in the manufacturing sequence. A step has step tags that are input values which are loaded into the associated phase, and output values which are data loaded from the

Equipment Phase

.

Step input tag values are assigned to phase input parameters when the step is activated (automatically when configured on the

Equipment Phase

) and when requested by the phase’s logic.

Step output tags are assigned phase output parameter values when the phase becomes COMPLETE, STOPPED, or ABORTED (automatically when configured on the

Logix Designer

) and when requested by the phase logic.

Links connect steps, transitions, and branching structures.

A link connects the bottom connector of an element to the top connector of a following element. A link may only be added between elements that are not already connected and in a valid structure.

A transition, based on the evaluation of its expression, determines when preceding steps are STOPPED, RESET, and phases released. The transition also attaches and STARTS the phases of following steps.

Transitions go active when the user-defined expression they contain evaluates to TRUE. When the transition goes active, the preceding steps are reset and the next step is started.