Mitsubishi Melservo-J2-Super series Instruction Manual page 60

4. OPERATION AND FUNCTIONS
4.1.5 Setting of full closed encoder electronic gear
(1) Parameters
No. Abbreviation
65 FCM
66 FCD
Note 1. When changing the setting of the above parameter, set "000F" in parameter No. 40 "parameter block ( BLK)".
2. After setting the parameter marked , switch power off once. The setting is made valid by switching power on again.
(2) Parameter setting method
For the full closed electronic gear setting, set the ratio of the full closed encoder feedback to the servo
motor encoder feedback.
FCM
FCD
Make setting so that the full closed electronic gear
1 FCM 100
< <
100 FCD
This setting must be made for all linear scales or rotary encoders.
[Setting example 1] When the servo motor is directly coupled with a ballscrew and the linear scale resolution is
0.05 m
Servo motor
Calculate the number of linear scale pulses per servo motor revolution.
[Setting example 2] When a rotary encoder at roll feed detection end is used for detection
Servo motor
Pulley diameter d1
When the pulley diameters or reduction ratios differ, consider that in calculation.
For the rotary encoder, make calculation using the number of pulses multiplied by 4.
CAUTION
Name and Function
Full closed electronic gear numerator
Set the numerator of the electronic gear relative to the
full closed encoder pulse.
Full closed electronic gear denominator
Set the denominator of the electronic gear relative to
the full closed encoder pulse.
Number of servo motor encoder pulses per servo
Number of full closed encoder pulses per servo
range.
1
Linear scale
Ballscrew lead / linear scale resolution
FCM 131072
FCD 80000
Pulley diameter d2
Rotary encoder
5000pulse/rev
30mm
FCM 131072 20
FCD 20000 30
If a wrong value is set in the linear scale electronic gear (parameter No. 65,
66), normal operation may not performed.
It may also cause a servo alarm (AL. 42) during positioning operation.
FCM
does not fall outside the
FCD
<Conditions>
Servo motor resolution
Ballscrew lead
Linear scale resolution
4mm/0.05 m
1024
625
20mm
<Conditions>
Servo motor resolution
Servo motor side pulley diameter
Rotary encoder side pulley diameter
Rotary encoder resolution
8192
1875
4 - 5
Initial
Unit
Value
1
1
: 131072pulse/rev
: 4mm
: 0.05 m
80000pluse
: 131072pulse/rev
: 30mm
: 20mm
: 5000pulse/rev
(20000 pulses/rev after multiplication by 4)
Setting
Range
1
to
65535
1
to
65535