1756-PM003H-EN-E, SFC and ST Programming Languages ...

5-6 Program a Sequential Function Chart
End a Selection Branch
1. Select the last transition of each path in the branch. To select the
transitions, you can either:
• Click and drag the pointer around the transitions that you
want to select.
• Click the first transition. Then press and hold [Shift] and click
the rest of the transitions that you want to select.
2. On the SFC toolbar, click
3. Add the step that follows the selection branch.
B
A
green dot
4. To wire the selection branch to the step, click the top pin of the
step A and then click the horizontal line of the branch B . A
green dot shows a valid connection point.
Set the Priorities of a
Selection Branch
By default, the SFC checks the transitions that start a selection branch
from left to right. If you want to check a different transition first,
assign a priority to each path of the selection branch. For example, it
is a good practice to check for error conditions first. Then check for
normal conditions.
To assign priorities to a selection branch:
1. Right click the horizontal line that starts the branch and select
Set Sequence Priorities.
Publication 1756-PM003H-EN-E (excerpt from 1756-PM001H-EN-P) - August 2005