Mitsubishi Electric MELSERVO-J4 Series Instruction Manual page 528

Confirmation of load-side encoder position data
Check the load-side encoder mounting and parameter settings for any problems.
Depending on the check items, MR Configurator2 may be used.
Refer to the following for the data displayed on the MR Configurator2.
Page 533 About MR Configurator2
When checking the following items, the fully closed loop control mode must be set. For the setting of control mode, refer to the
following.
Page 522 Selection of fully closed loop system
No. Check item
1 Read of load-side encoder position data
2 Read of load-side encoder home
position (reference mark, Z-phase)
3 Confirmation of load-side encoder
feedback direction
(Setting of load-side encoder polarity)
4 Setting of load-side encoder electronic
gear
16 FULLY CLOSED LOOP SYSTEM
526
16.3 Operation and functions
Confirmation method and description
With the load-side encoder in a normal state (mounting, connection, etc.), the load-side cumulative
feedback pulses value is counted normally when the load-side encoder is moved.
When it is not counted normally, the following factors can be considered.
1. An alarm occurred.
2. The installation of the load-side encoder was not correct.
3. The encoder cable was not wired correctly.
With the home position (reference mark, or Z-phase) of the load-side encoder in a normal condition
(mounting, connection, etc.), the value of load-side encoder information 1 is cleared to 0 when the home
position (reference mark, or Z-phase) is passed through by moving the load-side encoder.
When it is not cleared, the following factors can be considered.
1. The installation of the load-side encoder was not correct.
2. The encoder cable was not wired correctly.
Confirm that the directions of the cumulative feedback pulses of servo motor encoder (after gear) and the
load-side cumulative feedback pulses are matched by moving the device (load-side encoder) manually in
the servo-off status. If mismatched, reverse the polarity.
When the servo motor and load-side encoder operate synchronously, the servo motor-side cumulative
feedback pulses (after gear) and load-side cumulative feedback pulses are matched and increased.
If mismatched, review the setting of fully closed loop control feedback electronic gear ([Pr. PE04], [Pr.
PE05], [Pr. PE34], and [Pr. PE35]) with the following method.
1) Check the servo motor-side cumulative feedback pulses (before gear).
2) Check the load-side cumulative feedback pulses.
3) Check that the ratio of above 1) and 2) has been that of the feedback electronic gear.
Command
Servo motor-side cumulative
feedback pulses (after gear)
2) Load-side cumulative
feedback pulses
+
Servo motor
-
3) Electronic
gear
1) Servo motor-side cumulative
feedback pulses (before gear)
Linear
encoder