FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Positioning Control Edition
Built-in Positioning Functions
9 One-speed Interrupt constant quantity feed -DVIT Instruction
9.4 Important Points
B - 132
9.4 Important Points
→ For details on the instruction activation timing, refer to Section 4.7.
• If the speed is too high for the number of pulses specified by , the frequency will be reduced so that
the speed can be reduced within the specified number of output pulses.
• If there is a possibility for the interrupt input instruction to be turned on during acceleration, specify the
number of pulses so that the relation can be set to "number of output pulses ≥ number of pulses needed for
acceleration + number of pulses needed for deceleration".
If the relation is set to "number of output pulses < number of pulses needed for acceleration + number of
pulses needed for deceleration", the operation will be as shown in the following figure:
• If the interrupt input turns ON before execution of the instruction, the operation will be performed in the
same way as the DRVI instruction.
• If an operand is changed during instruction execution, the change will be ignored and the operation will not
be affected. To reflect the change on the operation, turn off the command contact of the instruction, and
then turn it on again.
• If the instruction activation contact is turned off during operation, the speed will decelerate and the
operation will stop. In this case, the "Instruction execution complete" flag (M8029) will not be turned on.
• Input the interruption signal before the number of output pulses reaches 4,294,967,296. If the number of
pulses reaches 4,294,967,296 before inputting the interruption signal, the operation will stop, and the
"Instruction execution complete" flag (M8029) will be turned on.
→ For details on "Instruction execution complete" flag,
refer to Subsection 4.7.4.
• If the "pulse output monitor" (BUSY/READY) flag is on, a positioning instruction (including PLSR and
PLSY) that uses the same output cannot be executed.
If the "pulse output monitor" (BUSY/READY) flag is still on after the instruction activation contact is turned
off, do not execute a positioning instruction (including PLSR and PLSY instructions) that uses the same
output number.
• If the forward limit relay or the reverse limit relay in the operation direction is turned on, the speed will
decelerate and the operation will stop. In this case, the "Instruction execution abnormal end" flag (M8329)
will turn when execution of the instruction is complete.
→ For details on "Instruction execution abnormal end" flag, refer to Subsection 4.7.4.
S
1
Output pulse
frequency
specified by
S
2
•
S
1
•
Actual output
pulse frequency
Number of output
pulses specified by
Interrupt input
Output pulse
frequency
specified by
S
2
•
S
1
•
Number of output
pulses specified by
Interrupt input