High−level Instructions
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Precautions during programming
If the elapsed value area has been specified as a hold type memory area, the elapsed value acts in
accordance with the contents being retained.
Be aware that, when an operation is begun, the set values are not automatically preset to the elapsed value
area. To preset these values, the reset input must be switched from the “on” to the “off” state.
When combining the F118 (UDC) instruction with an AND stack instruction or POP stack instruction, be
careful that the programming is correct.
Cautions on count input detection
In a F118 (UDC) instruction, the increment or decrement takes place when the rise of the count input
from off to on is detected.
If the count input remains continuously on, since counting will only take place at the rise, no further counting
will take place.
In cases where the count input is initially on such as when the mode is changed to RUN or the power is turned
on with the mode set to RUN, increment or decrement operation will not take place at the first scan.
Count intput
Operation of
instruction
No count done
Count done
RUN
(Power: on)
When you use the F118 (UDC) instruction with one of the following instructions that changes the order of the
execution of instructions, be aware that the operation of the instructions will differ depending on the timing of
their execution and their count input.
− MC to MCE instructions
− JP to LBL instructions
− F19 (SJP) to LBL instructions
− LOOP to LBL instructions
− CNDE instruction
− Step ladder instructions
− Subroutine instructions
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