Checking Position Data Of The Load-Side Encoder - Mitsubishi Electric MELSERVO-J5 User Manual

Checking position data of the load-side encoder

Precautions
Depending on the check items, MR Configurator2 may be used. Refer to "Help" of MR Configurator2 for the data displayed on
the MR Configurator2.
Check the load-side encoder mounting and parameter settings for any problems.
No. Check item
1 Reading the position data of the load-
side encoder
2 Reading the home position of the load-
side encoder
(reference mark, Z-phase)
3 Checking the load-side encoder
feedback direction
(setting the polarity of the load-side
encoder)
4 Setting the electronic gear for the load-
side encoder
Confirmation method and description
When a load-side encoder that is installed and connected correctly is operated, the value for load side
encoder cumulative feedback pulses is counted correctly.
If the value is not counted correctly, the following are likely causes.
(1) An alarm occurred.
(2) The load-side encoder is not installed correctly.
(3) The encoder cable is not wired correctly.
If the home position (reference mark, or Z-phase) of the load-side encoder is in a normal condition
(mounting, connection, etc.), the value of load-side encoder information 1 is cleared to 0 when the load-side
encoder is moved to pass through the home position (reference mark, or Z-phase).
If the value is not cleared, the following are likely causes.
(1) The load-side encoder is not installed correctly.
(2) The encoder cable is not wired correctly.
Move the device (load-side encoder) manually in servo-off status to confirm that the directions of the
cumulative feedback pulses of the servo motor encoder (after taking the gear into consideration) and the
load-side cumulative feedback pulses are matched.
If the directions are mismatched, reverse the polarity.
When the servo motor and the load-side encoder move synchronously, the servo motor-side cumulative
feedback pulses (after taking the gear into consideration) and load side encoder cumulative feedback pulses
increase by the same amount.
If the cumulative feedback pulses are mismatched, use the following procedure to review the settings of the
fully closed loop control feedback electronic gear ([Pr. PE04 Fully closed loop control - Feedback pulse
electronic gear 1 - Numerator] and [Pr. PE05 Fully closed loop control - Feedback pulse electronic gear 1 -
Denominator]).
(1) Check the servo motor-side cumulative feedback pulses (before taking the gear into consideration).
(2) Check the load-side cumulative feedback pulses.
(3) Check that the ratio of (1) to (2) mentioned above is the same as the feedback electronic gear ratio.
Command
Servo motor-side cumulative
feedback pulses (after gear)
(2) Load-side encoder cumulative feedback pulses
+
Servo motor
-
(3) Electronic gear
(1) Servo motor-side cumulative
feedback pulses (before gear)
12 USING A FULLY CLOSED LOOP SYSTEM
12
Linear encoder
461
12.4 Startup