MITSUBISHI ELECTRIC MR-J2S- CL - Manual (Page 154)

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5. PARAMETERS
5.2 Detailed explanation
5.2.1 Electronic gear
CAUTION False setting will result in unexpected fast rotation, causing injury.
POINT
The guideline for setting the electronic gear is
CMX
CDV 1
10
1000 .
If you set any value outside this range, noise may be produced during
acceleration/deceleration or operation not performed at the preset speed
or acceleration/deceleration time constant.
After setting the parameter No.4, 5 value, switch power off, then on to
make that setting valid. In this case, execute a home position return
again.The absolute position detection system also requires a home
position return.
(1) Concept of electronic gear
Use the electronic gear (parameters No.4, 5) to make adjustment so that the servo amplifier setting
matches the moving distance of the machine. Also, by changing the electronic gear value, the machine
can be moved at any multiplication ratio to the moving distance on the servo amplifier.
Parameters No. 4
Parameters No. 5 CMX
CDV
Electronic gear
Parameters No. 4, 5
Encoder feedback pulses
CMX
CDV Deviation
counter
Motor
Encoder
Mo
v
in
g
d
ist
a
n
ce +
-
The following examples are used to explain how to calculate the electronic gear value:
POINT
The following specification symbols are needed for electronic gear
calculation:
Pb : Ballscrew lead [mm(in.)]
n : Reduction ratio
Pt : Servo motor resolution [pulse/rev]
S : Travel per servo motor revolution [ m/rev]
(a) Ballscrew setting example
Machine specifications
Ballscrew lead: Pb 10 (0.39) [mm(in.)]
Reduction ratio: n 1/2
Servo motor resolution: Pt 131072 [pulse/rev]
Servo motor 131072[pulse/rev]
n
NM
NL
Pb=10(0.39)[mm(in.)]
n=NL/NM=1/2
CMX
CDV S
p
t
5000
131072
625
32768 p
t
n 1000 p
b
131072
1/2 10 1000
Hence, set 32768 to CMX and 625 to CDV.
(b) Conveyor setting example
Machine specifications
Pulley diameter: r 160 (6.30) [mm(in.)]
Reduction ratio: n 1/3
Servo motor resolution: Pt 131072 [pulse/rev]
Servo motor
131072[pulse/rev]
r=160(6.30)[mm(in.)]
n
NM NL
n=NL/NM=1/3
CMX
CDV
p
t
S
32768
41888
167551.61
131072 p
t
n r 1000
131072
1/3 160 1000