Omron SYSMAC CX-Programmer 8.1, Operation Manual

Page: 71 / 154

Elements of SFC Section 2-3
55
Action Execution Timing for Action Qualifiers (AQs)
Step Status
AQ
N
P
P1
P0
L
D
S
SL
SD
DS
Active status
Inactive status
* Executed just twice when the
final scan function is
enabled.
Executed just once when the
final scan function is
disabled.
(When the action is a bit, it is
ON for just one cycle.)
Termination of execution
by the “R” AQ
Executed
Not Executed
*
R
Set Value
Set Value
Set Value
Set Value
Set Value
Set Value
Set Value
Set Value
Set Value
Actions
An action is executed when a step changes to the active status. Actions can be
specified as either of the following:
•
Bit (Boolean variable or actual address)
•
Action program name
When an action is defined as a Boolean variable (bit), the bit is turned ON when the
action is executed, and turned OFF when the action is stopped.
When an action is defined as an action program name, the action program is executed
when the action is executed, and stopped when the action is stopped.
Note: Multiple steps can run the same action program within a single execution of the SFC. Only
simultaneously activated steps are affected by single scan execution.
Boolean Variable or Actual Address (Bit)
An action block can be defined as a Boolean variable or actual address (bit). When the
step becomes active, the Boolean variable or actual address (bit) is turned ON
according to the AQ, and the bit is turned OFF if the action stops.