Elements of SFC
Section 2-3
56
Action Program
If the action is executed, the specified action program is executed.
Note:
The same action program can be specified in multiple steps of an SFC chart. When two or
more steps are active at the same time and have the same action program specified, that
action program is executed just once in a cycle.
An action program can be coded using either Ladder or ST as the language.
Ladder Program
An action block can be defined as a ladder program.
Some instructions are not supported when defining an action program in ladder logic.
For details, refer to
1-5-4 Ladder Language Instructions Can Not Be Used in Action
Programs and Transition Programs
.
In ladder programs, the
Reset Output at Final Scan
Option can be selected in the
action’s properties to turn OFF the ladder program’s outputs when the step is inactive.
If function blocks are used in the ladder program, the status of outputs used in the
function blocks will be held.
Note:
If the action qualifier is set to “N”, the ladder program may not be able to correctly detect
the step “rising” to the active status. For this reason, if a process is to be executed only
once, upon the activation of the step, the “P1” action qualifier should be used.
ST Program
An action block can be defined as an ST program.
For specifications on the ST language used when defining transition programs in ST,
refer to
Part 2: Structured Text (ST)
in the
CX-Programmer Operation Manual Function
Blocks/Structured Text
(Cat. No. W447).
Action Execution Order
Refer to
1-5-2 on Action Program Precautions
for information on the order of execution
of actions within a step and the actions within multiple active steps.
Checking Action Usage
It is possible to display a list of all of the actions (Boolean bit specifications and action
programs) in a single SFC program.
Select Program – Action used list
. The following dialog box will be displayed, so that
the use of the actions can be checked.
•
Selecting the Main SFC
•
Selecting a Subchart
•
Steps are displayed from the top in the order in which they are registered.
Multiple active subcharts are executed in the order in which they are registered,
i.e., from top down as they are displayed in the dialog box.
Summary of Contents for SYSMAC CX-Programmer 8.1
Page 1: ...Operation Manual SFC Programming SYSMAC WS02 CXPC1 V8 CX Programmer Ver 8 1 Cat No W469 E1 04...
Page 2: ...ii CX Programmer Ver 8 1 WS02 CXPC1 V8 Operation Manual SFC Programming Revised February 2009...
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Page 56: ...Precautions When Creating SFC Programs Section 1 5 40...
Page 118: ...Monitoring Section 4 5 102...
Page 150: ...Index 134...
Page 152: ...Revision History 136...
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