Mitsubishi Electric MELSEC-L LD75D, User Manual

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119
CHAPTER 5 DATA USED FOR POSITIONING CONTROL
5
5.
2
List
of
P
a
ramet
e
rs
(2) [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 LD75.
The following paragraphs explain how to set the individual parameters [Pr.2], [Pr.3], and [Pr.4].
*1
(assuming that
the unit "mm" is selected with [Pr.1].)
The movement amount per pulse is given by the following expression:
• Movement amount per pulse = Movement amount per rotation (Al) / No. of pulses per rotation (Ap)
*1 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. (

Page 520, Section
12.3.2)
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.
(a) Setting range
*1 1 to 32767: Set as a decimal
32768 to 65535: Convert into hexadecimal and set
(3) [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 Electric servo amplifier, set the value given as the "resolution per servomotor
rotation" in the speed/position detector specifications.
*1
• No. of pulses per rotation (Ap) = Resolution per servomotor rotation
*1 When the "Resolution per servomotor revolution" of Mitsubishi Electric servo amplifier exceeds 65535 pulses, make
setting after referring to the Servo Amplifier Instruction Manual.
[Pr.1] setting value Value set with GX Works2 (unit)
Value set with program (unit)
*1
0: mm 0.1 to 6553.5 (

m)
1 to 65535 (

10
-1

m)
1: inch 0.00001 to 0.65535 (inch)
1 to 65535 (

10
-5
inch)
2: degree 0.00001 to 0.65535 (degree)
1 to 65535 (

10
-5
degree)
3: pulse 1 to 65535 (pulse) 1 to 65535 (pulse)