MITSUBISHI ELECTRIC MR-J2S- CP - Manual (Page 156)

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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
This parameter is made valid when power is switched off, then on after
setting, or when the controller reset has been performed.
The range of the electronic gear setting is
CMX
CDV 1
10
1000. If you set
any value outside this range, a parameter error (A37) occurs.
After setting the parameter No.4, 5 value, switch power off, then on to
make that setting valid.
(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.
Parameter No. 4
Parameter No. 5 CMX
CDV
Electronic gear
Parameters No. 4, 5
Encoder feedback pulses
CMX
CDV Deviation
counter
Motor
Encoder
M
ov
ing
d
is
tanc
e +
-
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 [mm/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
1250
32768 p
t
n 1000 p
b
131072
1/2 10 1000
Hence, set 32768 to CMX and 1250 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
Reduce CMX and CDV to the setting range or less, and round off the first decimal place.
Hence, set 32768 to CMX and 41888 to CDV.