Electronic Gear Function - Mitsubishi Electric MELSEC Q Series User Manual

11.1

Electronic Gear Function

The "electronic gear function" controls machine movement amount per one command pulse by multiplying command
pulse output of the QD73A1.
Positioning is much more flexible with the use of this function, eliminating the process of selecting a detector according
to the machine system.
(1) Details of the electronic gear function
Machine movement amount per one pulse is adjusted inside the QD73A1.
Electronic gear is active on all of OPR control, major positioning control, and JOG operation.
Setting data
Set numerator and denominator of command pulse multiplication for electronic gear to parameters.
Satisfy the following condition when setting a numerator (CMX) and a denominator (CDV).
1 CMX
50 CDV
If the setting range is exceeded, the error "Denominator of command pulse multiplication for electronic gear
Outside the setting range" (error code: 3) occurs.
When the electronic gear function is used, positioning speed and movement amount are multiplied by the
specified value.
When there are decimal pulses, the fractions are maintained inside and accumulated for the next command.
The following is an example of the use of electronic gear.
A positioning system using the following worm gear
Ex.
• Worm gear lead: 10mm
• Feedback pulses from the servomotor: 12000pulse/rev
When the electronic gear function is not used, the feed rate (movement amount per pulse) has fractions.
10
=
12000
In this system, the fractions can be avoided using the electronic gear function and setting numerator and
denominator as follows: CMX/CDV = 12
10
' =
12000
QD73A1
Electronic Deviation
gear counter
Number of Accumulated pulses
command
pulses
CMX
Command
pulse
CDV
50
= mm/pulse
0.000833
12 = 0.01mm/pulse
CHAPTER 11 CONTROL SUB FUNCTIONS
D/A
converter
Analog voltage
Multiplication
Drive unit
Speed
command
Servo
amplifier
feedback pulse
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