Introduction

Links connect steps and transitions, transitions and steps etc.

Properties of Links

Links have the following properties:

• Links between objects of the same type (step with step, transition with transition, etc.) are not possible

• Links are possible between:

  • unlinked object outputs and

  • unlinked or linked step inputs

    (i.e. multiple step inputs can be linked)

• Overlapping links and other SFC objects (step, transition, jump, etc.) is not possible

• Overlapping links and links is possible

• Crossing links with links is possible and is indicated by a "broken" link:

  

• Links consist of vertical and horizontal segments

• Standard signal flow in a sequence string is from top to bottom. To create a loop however, links can be made from below to a step above. This applies to links from transitions, parallel branches or alternative joints to a step. In these cases, the direction of the link is indicated with an arrow symbol:

  

• With links, there is a difference between a String Jump and a String Loop