EURA SD20-G Series, Manual

Page: 156 / 353

SD20-G Series
156
②
Electronic gear ratio switchover
If two groups of electronic gear ratio have large difference, motor speed fluctuates wildly when electronic gear
ratio swithover. Po306 position command filter can smooth position switchover.
Po339
Electronic gear ratio selection
Position
Setting range Setting unit
Mfr’s value
When enabled
0~2 N/A 0 Effective Immediate
0: First electronic gear ratio
1: Second electronic gear ratio
2: Two groups of electronic gear ratio swithchover
4) Instruction
The deceleration ratio is n/m, electronic gear numerator is B, and electronic gear denominator is A, so the setting
value of electronic gear ratio is:
Note: The deceleration ratio is n/m where m is the rotation of the servo motor and n is the rotation of the load shaft.
B/A=Po304/ Po305=(No. of encoder pulses×4/travel distance per load shaft rotation)×
（
m/n
）
The actual meaning of electronic gear is:
Command pulse input
Pulses numbers are X
Y=X
×
A
B
A
B
Position command
* If the ratio is outside the setting range, reduce the fraction (both numerator and denominator) until you obtain
integers within the range. Be careful not to change the electronic gear ratio (B/A).
Electronic gear ratio setting range: 0.01 ≤ Electronic gear ratio (B/A) ≤ 100
If the electronic gear ratio is outside this range, the control precision will decrease.
Ex
：
The following example shows electronic gear ratio settings for ball screw which pitch is 6mm.
Setting range Setting unit
Mfr’s value
When enabled
1~65535 N/A 10000 Effective Immediate
Po344
2
ed
group electronic gear numerator
Position
Setting range Setting unit
Mfr’s value
When enabled
0~2147483647 N/A 0 Effective Immediate
Po346
2
ed
electronic gear denominator
Position
Setting range Setting unit
Mfr’s value
When enabled
1~2147483647 N/A 10000 Effective Immediate