Sanyo Denki Sanmotion R 3E S, Instruction Manual, Page: 392 / 514

9. Dedicated function
9-11
■
Feedback pulse electronic gear
Sets the electronic gear ratio for converting motor encoder resolution to external encoder
resolution.
This parameter is used for calculation of dual position error (position error between motor
encoder and external encoder).
Be valid after control power cycle.
Relation equation of electronic gear ratio is follows.
✔ Multiplied 4 to encoder resolution, in case of incremental encoder.
 Setting sample 1 (Motor encoder is absolute encoder)
[Use condition]
・
Move distance of work per 1 turn of motor axis: 10mm
・
Minimum resolution of external encoder: 1.0×10 -3 mm ( =1.0 μ m)
・ System parameter ID15 “Absolute encoder resolution”: 131072 division
[Setting value]
・
FBPLSPN = 10mm/(1.0×10 -3 ) = 10000 Pulse
・
FBPLSPD = Absolute encoder resolution = 131072 Pulse
 Setting sample 2 (Motor encoder is incremental encoder)
[Use condition]
・
Move distance of work per 1 turn of motor axis: 10mm
・ Minimum resolution of external encoder: 1.0×10
-3
mm ( =1.0 μ m)
・
System parameter ID17 “Incremental encoder resolution”: 2000 P/R
[Setting value]
・ FBPLSPN = 10mm/(1.0×10
-3
) = 10000 = 10000 Pulse
・
FBPLSPD = Incremental encoder resolution×4 = 2000×4 = 8000 Pulse
 Setting sample 3 (Motor encoder is absolute encoder)
[Use condition]
・
Move distance of work per 1 turn of motor axis: 10/3 mm
(Work moves 10 mm by 3 turns of motor.)
・
Minimum resolution of external encoder: 1.0×10 -3 mm ( =1.0 μ m)
・
System parameter ID15 “Absolute encoder resolution”: 131072 division
[Setting value]
・
FBPLSPN = (10/3) /(1.0×10 -3 ) = 10000 / 3 = 3333 .333
･･･
= 3333 Pulse
Indivisible. So, set the value as follows in this case.
・
FBPLSPN = 10/(1.0×10 -3 ) = 10000 Pulse
・ FBPLSPD = Absolute encoder resolution×3 = 131072×3 = 393216 Pulse
✔
When calculation values of FBPLSPN or FBPLSPD have decimal part, round off the value to
the whole number. However, dual position error is not able to calculate accurate by round off,
and it might detect “Dual position error excess (AL.D5).
So, in this case, set 0 to GroupB ID19 "Dual position error warning level" and GroupB ID1A
"Dual position error excess value", for excepting warning and alarm detection.
Group ID Symbol Name Setting range Unit
System 24 FBPLSPN
Numerator of feedback pulse
electronic gear
1 to 2,097,152 Pulse
System 25 FBPLSPD
Denominator of feedback
pulse electronic gear
1 to 2,097,152
Pulse
FBPLSPN [SY-24]
FBPLSPD [SY-25]
=
Feedback encoder pulse amount per 1 turn of motor
Motor encoder resolution