Mitsubishi Electric MELSEC iQ-F Series - Page 60

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6 ST LANGUAGE
6.1 Configuration
■When a rising execution instruction or a falling execution instruction is used
Shown here is the operation when a rising execution instruction or an fall execution instruction is used in an IF statement or a
CASE statement.
*1 This is a fall (ON to OFF), but the instruction is not executed because the condition in the IF statement or the CASE statement is not
satisfied.
Ex.
When the PLS instruction (rising execution instruction) is used in an IF statement
Condition Result of operation
Conditional
expression of an IF
statement or a
CASE statement
Condition to
execute an
instruction (EN)
Result of the ON/
OFF judgment of
the instruction at
the time of the
previous scan
Result of the ON/
OFF judgment of
the instruction
Rising execution
instruction
Falling execution
instruction
Agreement of TRUE or
CASE
TRUE ON ON Not executed Not executed
OFF ON Executed Not executed
FALSE ON OFF Not executed Executed
OFF OFF Not executed Not executed
Disagreement of FALSE
or CASE
TRUE ON OFF Not executed Not executed
*1
OFF OFF Not executed Not executed
FALSE ON OFF Not executed Not executed
*1
OFF OFF Not executed Not executed
(1) If bLabel0 = OFF (the condition expression in the IF statement is
FALSE), the ON/OFF judgment result is OFF. The PLS
instruction is not executed. (bLabel10 = OFF does not change.)
(2) If bLabel0 = ON (the condition expression in the IF statement is
TRUE) and bLabel1 = OFF (the condition for executing the
instruction is OFF), the ON/OFF judgment result is OFF. The PLS
instruction is not executed. (bLabel10 = OFF does not change.)
(3) If bLabel0 = ON (the condition expression in the IF statement is
TRUE) and bLabel1 = ON (the condition for executing the
instruction is ON), the ON/OFF judgment result is OFF to ON (the
condition for a rise is satisfied). The PLS instruction is executed.
(bLabel10 turns ON for once scan only.)
IF bLabel0 THEN
PLS(bLabel1,bLabel10);
END_IF;
ON
OFF
OFF
OFF
OFF
ON
(1) (2)
ON
ON
ON
(3)
bLabel0
bLabel10
bLabel1
1 scan
ON/OFF
judgment
result