Mitsubishi Electric MELSERVO-J4 series, Instruction Manual

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14 USING A LINEAR SERVO MOTOR
14.3 Operation and functions
473
14
Linear encoder resolution setting
• To enable the parameter values, cycle the power after setting.
• If an incorrect value is set for [Pr. PL02]/[Pr. PL03], the linear servo motor may not operate properly, or [AL.
27]/[AL. 42] may occur during the positioning operation/the magnetic pole detection.
Set the ratio of the electronic gear to the linear encoder resolution with [Pr. PL02 Linear encoder resolution - Numerator] and
[Pr. PL03 Linear encoder resolution - Denominator].
■
Parameter setting
Set the values that apply to the following equation.
■
Parameter setting example
When the linear encoder resolution is 0.5

m
The following shows the simplified chart for the setting values of [Pr. PL02] and [Pr. PL03].
Magnetic pole detection
Set [Pr. PE47 Torque offset] to "0 (initial value)" before executing the magnetic pole detection.
Before the positioning operation of the linear servo motor, make sure to perform the magnetic pole detection. When [Pr. PL01]
is set to the initial value, perform the magnetic pole detection only at the first servo-on after the power is turned on.
The magnetic pole detection includes the following two methods. Each method has advantages and disadvantages. Select a
magnetic pole detection method suitable for your usage.
The position detection method is selected in the initial setting.
Parameter Linear encoder resolution [

m]
0.01 0.02 0.05 0.1 0.2 0.5 1.0 2.0
Setting value [Pr. PL02] 1 1 1 1 1 1 1 2
[Pr. PL03] 100 50 20 10 5 2 1 1
Magnetic pole detection Advantage Disadvantage
Position detection method 1. The magnetic pole detection has a high degree
of accuracy.
2. The adjustment procedure at the magnetic pole
detection is simple.
1. The travel distance at the magnetic pole
detection is large.
2. For equipment with small friction, the initial
magnetic pole detection error may occur.
Minute position detection method 1. The travel distance at the magnetic pole
detection is small.
2. Even for equipment with small friction, the
magnetic pole detection is available.
1. The adjustment procedure at the magnetic pole
detection is complex.
2. If a disturbance occurs during the magnetic
pole detection, [AL. 27 Initial magnetic pole
detection error] may occur.
[Pr. PL02 Linear encoder resolution - Numerator]
= Linear encoder resolution [ μ m]
[Pr. PL03 Linear encoder resolution - Denominator]
[Pr. PL02]
= Linear encoder resolution = 0.5 μ m =
[Pr. PL03]
2
1