Mitsubishi Electric MELSERVO-J4 series, Instruction Manual

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14 USING A LINEAR SERVO MOTOR
14.3 Operation and functions
481
14
Home position return
The incremental linear encoder and the absolute position linear encoder have different reference home
positions at the home position return.
Incremental linear encoder
■ When the linear encoder home position (reference mark) exists in the home position return
direction
Reference home positions are necessary to perform home position return. In the initial setting of [Pr. PL01], reference home
positions are made at every 1048576 pulses starting from the linear encoder home position (reference mark) first passed
through after a home position return. Change the setting value of [Pr. PL01] according to the linear encoder resolution.
The following shows the relation between the stop interval at the home position return and the linear encoder resolution. For
example, when the linear encoder resolution is 0.001

m and the parameter for the stop interval at the home position return,
[Pr. PL01], is set to "_ 5 _ _" (16777216 pulses), the stop interval is 16.777 mm. The value inside a bold box indicates the
recommended stop interval for each linear encoder resolution.
CAUTION
• If the resolution or the stop interval (the third digit of [Pr. PL01]) of the linear encoder is large, the linear servo motor may crash into the stroke end, which is
very dangerous.
[Pr. PL01]
Stop interval setting at the home position return
Setting
value
Stop interval [pulse]
0 8192
1 131072
2 262144
3 1048576 (initial value)
4 4194304
5 16777216
6 67108864
Pr. PL01 Linear encoder resolution [ μ m]
0.001 0.005 0.01 0.02 0.05 0.1 0.2 0.5 1 2
[Unit: mm]
_ 0 _ _ 8192
_ 1 _ _
_ 2 _ _
_ 3 _ _
_ 4 _ _
_ 5 _ _
_ 6 _ _
0.008
131072
262144
1048576
4194304
16777216
67108864
0.041
0.131
0.262
1.049
4.194
16.777
67.109
0.082
0.655
1.311
5.243
20.972
83.886
335.544
0.164
1.311
2.621
10.486
41.943
167.772
671.089
0.410
2.621
5.243
20.972
83.886
335.544
1342.177
0.819
6.554
13.107
52.429
209.715
838.861
3355.443
1.638
13.107
26.214
104.858
419.430
1677.722
6710.886
4.096
26.214
52.429
209.715
838.861
3355.443
13421.773
8.192
65.536
131.072
524.288
2097.152
8388.608
33554.432
16.384
131.072
262.144
1048.576
4194.304
16777.216
67108.864
262.144
524.288
2097.152
8388.608
33554.432
134217.728
Stop
interval
[pulse]