Mitsubishi QD75P1N User Manual page 123

5 DATA USED FOR POSITIONING CONTROL
Pr.2 to Pr.4 Movement amount per pulse
These parameters define the amount of movement achieved by each single pulse
within a pulse train output by the QD75.
The following paragraphs explain how to set the individual parameters
Pr.3 Pr.4
, and assuming that the unit "mm" is selected with
The movement amount per pulse is given by the following expression:
Movement amount per pulse =
Due to the mechanical tolerance, the actual movement amount may differ
slightly from the instructed movement amount. The error can be compensated
by adjusting the movement amount per pulse defined here.
(Refer to Section 12.3.2 "Electronic gear function".)
POINT
If the movement amount per pulse is less than 1, command frequency variations
will occur.Smaller setting will increase variations and may cause machine
vibration.If the movement amount per pulse becomes less than 1, also use the
electronic gear function of the drive unit and make setting so that the movement
amount per pulse is 1 or greater.
[Table 1]
Pr.1 setting value
0 : mm
1 : inch
2 : degree
3 : pulse
1 to 32767 : Set as a decimal
32768 to 65535 : Convert into hexadecimal and set
Pr.2 No. of pulses per rotation (Ap)
Set the number of pulses required for a complete rotation of the motor shaft.
If you are using the Mitsubishi servo amplifier, set the value given as the
"resolution per servomotor rotation" in the speed/position detector specifications.
No. of pulses per rotation (Ap) = Resolution per servomotor rotation
When the "Resolution per servomotor revolution" of Mitsubishi servo amplifier exceeds
65535 pulses, make setting after referring to the Servo Amplifier Instruction Manual.
Pr.3 Movement amount per rotation (Al), Pr.4 Unit magnification (Am)
The amount how the workpiece moves with one motor rotation is determined by
the mechanical structure.
If the worm gear lead (mm/rev) is PB and the deceleration rate is 1/n, then
Movement amount per rotation (AL) = PB × 1/n
Movement amount per rotation (Al)
No. of pulses per rotation (Ap)
Value set with peripheral device
(unit)
0.1 to 6553.5 ( μ m)
0.00001 to 0.65535 (inch)
0.00001 to 0.65535 (degree)
1 to 65535 (pulse)
5 - 19
MELSEC-Q
Pr.2
Pr.1
.
Value set with sequence program
(unit)
1 to 65535 ( × 10 -1
μ m)
1 to 65535 ( × 10 -5
inch)
1 to 65535 ( × 10 -5
degree)
1 to 65535 (pulse)
,