Omron SYSMAC CX-Programmer 8.1, Руководство по эксплуатации, Страница: 75 / 154

Elements of SFC Section 2-3
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2-3-4 Divergences
A divergence is a program control structure for SFC, in which two or more transitions
are connected after a single step.
A divergence is represented by a single horizontal line.
With a divergence, the process flow branches from a single step to two or more steps,
and active status is transferred for the branch on which the transition conditions are
met.
Step 2
Step 3
FALSE
Step 4
FALSE Trans2 Trans3
Administering Divergences
If a step before a divergence is in the active status and one of the transition conditions
after that divergence is met, the active status will be transferred, provided that the step
after the transition is currently in the inactive status.
•
If multiple transition conditions at a divergence are simultaneously met, priority will
be given to the left-most step. (Transition at a divergence can only take place for
one step.)
If the priority of the steps has been changed, however, active status will be
transferred according to the priority order.
Procedures:
Adding a Divergence
Right-click a step and select Add Divergence . To make a divergence with three or
more branches, right-click an existing divergence, and select Add Divergent
Transition Branch to add a branch.
Note: Right-click the divergence and clear the selection of the Use Default Transition
Precedence to display the execution order numerically, starting from 1. The order of
execution can be specified freely by double-clicking a corresponding number and
changing it.
2-3-5 Convergences
A convergence is a program control structure for SFC, in which a single step is
connected after two or more transitions.
A convergence is represented by a single horizontal line.
A convergence merges a process flow, which has been split into two or more process
flows (i.e. by a divergence).
Step 5
Step 3
FALSE
Step 4
FALSE Trans4 Trans5