Mitsubishi Electric FX3G SERIES Programming Manual page 199

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Cautions
1. Cautions when the LDP, LDF, ANDP, ANDF, ORP, or ORF instruction programmed in the same
step is executed two or more times within one operation cycle
When LDP, LDF, ANDP, ANDF, ORP or ORF instruction programmed in the same step is executed two or more times
within one operation cycle, the following operation results:
Programs executed two or more times
• Program between FOR and NEXT instructions
• Program which executes the same subroutine program from two or more
CALL instructions during one operation cycle
• Program which jumps to a label (P) in a smaller step number by CJ
instruction
Operation
1) When a device turns from OFF to ON
1st time: LDP, ANDP or ORP instruction turns ON.
2nd time and later: When the device status is the same as the time when the instruction was executed last, the
instruction turns OFF.
2) When a device turns OFF from ON
1st time: LDF, ANDF or ORF instruction turns ON.
2nd time and later: When the device status is the same as the time when the instruction was executed last, the
instruction turns OFF.
2. Cautions on writing during RUN
1) Instructions for falling edge pulse
When writing is completed during RUN for a circuit including an instruction for falling edge pulse (LDF, ANDF, or
ORF instruction), the instruction for falling edge pulse is not executed regardless of the ON/OFF status of the
target device of the instruction for falling edge pulse.
When writing is completed during RUN for a circuit including an instruction for falling edge pulse (PLF instruction),
the instruction for falling edge pulse is not executed regardless of the ON/OFF status of the operation condition
device.
It is necessary to set to ON the target device or operation condition device once and then set it to OFF for
executing the instruction for falling edge pulse.
2) Instructions for rising edge pulse
When writing is completed during RUN for a circuit including an instruction for rising edge pulse, the instruction for
rising edge pulse is executed if a target device of the instruction for rising edge pulse or the operation condition
device is ON.
Target instructions for rising edge pulse: LDP, ANDP, ORP, and pulse operation type applied instructions (such
as MOVP)
Contact ON/OFF status
(while writing is executed during RUN)
*1. PLS instruction is not executed.
Instruction for rising edge pulse
OFF
ON
7.5 LDP, LDF, ANDP, ANDF, ORP, ORF
Instruction for falling edge pulse
Not executed
*1
Executed
7 Basic Instruction
FNC 08
K
FOR
X000
FNC 09
NEXT
Not executed
Not executed
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