Setting Of Electronic Gear (For Melservo Series - Mitsubishi Electric Melsec-F FX3GC Series User Manual

FX /FX /FX /FX /FX
3S 3G 3GC 3U 3UC
Built-in Positioning Functions
4.6.2

Setting of Electronic Gear (For MELSERVO Series)

Use the electronic gear of the servo motor to set the transfer distance per pulse.
For details on the electronic gear setting, refer to the manual of the servo motor or servo amplifier, and set an
optimum value depending on the application.
Setting example 1:
To set the transfer distance per pulse to 10 m (if the machine uses a ball screw):
Machine specifications
Servo amplifier
Rated rotational speed of servo motor
Lead of ball screw (Pb)
Reduction ratio (mechanical gear) (n)
Resolution of servo motor (Pt)
CMX
×
= 
0
CDV
Set the electronic gear as follows:
CMX = 8, CDV = 1
In this case, when the main unit outputs the maximum output
pulse frequency (100 kHz), the servo motor rotational speed
will be as follows:
CMX
×
N =
0
CDV
8 60
×
=
1
4000
= 12000r/min > 3000r/min (Rated rotational speed of servo motor)
It is necessary to reduce the pulse frequency on the PLC side in order to reduce the servo motor rotational
speed so that it is less than the rated rotational speed.
Pulse output destination device
Y000
Y001
Y002
Y003
*1. Y002 is not available in FX
*2. Y003 is available only when two high-speed output special adapters are connected to the FX
PLC User's Manual - Positioning Control Edition
MR-C Series
3000r/min
10mm (0.4")/rev
1/2
4000PLS/REV
Pt 4000
-3 ×
= 10×10
n×P 1/2×10
b
60
× f
0
Pt
× 100000
Maximum speed setting device
*1
*2
PLC (14-point and 24-point type) and FX
3G
4.6 Setting of Various Items on Servo Amplifier (Drive Unit) Side
n=NL/NM=1/2
Servo motor
Pt = 4000 (PLS/REV)
8
f0 : Command pulse frequency [Hz]
=
1
CMX: Electronic gear
(numerator of command pulse
multiplying factor)
CDV : Electronic gear
(denominator of command pulse
multiplying factor)
N0 : Servo motor rotational speed [r/min]
 0 : Transfer distance per pulse [mm]
D8344,D8343
D8354,D8353
D8364,D8363
D8374,D8373
4 Before Programming
n
NL
NM Pb=10[mm](0.4")
/FX PLC.
3S 3GC
PLC.
3U
B - 77
A
B
Apx.