Mitsubishi Electric MELSEC-L LD75P User Manual page 524

(a) Setting range of Ap, Al, Am
Determined setting ranges are available for Ap, Al, and Am. The following shows the setting ranges.
Setting item
[Pr.2]
[Pr.3]
[Pr.4]
Refer to  Page 118, Section 5.2 for the information on detail settings. In addition, use the value set in "[Pr.3]
Movement amount per rotation" as movement amount per rotation (Al) to calculate movement amount per
pulse (A).
Movement amount per pulse (A) when "[Pr.1] Unit setting" is "0: mm"
Ex.
"[Pr.2] No. of pulses per rotation": 20000
"[Pr.3] Movement amount per rotation": 40000
"[Pr.4] Unit magnification": 1
If the value is beyond the setting range, setting values of each parameter can be decreased by canceling the
numerator and denominator with the movement amount per pulse (A) kept.
(2) Error compensation method
When position control is carried out by the "movement amount per pulse" set in the LD75 parameters, an error
sometimes occurs between the command movement amount (L) and the actual movement amount (L').
That error is compensated in the LD75 by adjusting the values in "[Pr.2] No. of pulses per rotation (Ap)", "[Pr.3]
Movement amount per rotation (Al)", and "[Pr.4] Unit magnification (Am)". (When "[Pr.1] Unit setting" is "0: mm")
(a) Definition
The "error compensation amount" used to carry out the error compensation is defined as follows.
The LD75 "movement amount per pulse" is calculated with the following equation.
Movement amount per pulse is "A", "[Pr.2] No. of pulses per rotation" is (Ap), "[Pr.3] Movement amount per
rotation" is (Al), and "[Pr.4] Unit magnification" is (Am).
522
No. of pulses per rotation (Ap)
Movement amount per rotation (Al)
Unit magnification (Am)
Movement amount per pulse (A) =
Error compensation amount =
A =
1 to 65535
-1
40000 × 10
× 1
20000
Actual movement amount (L')
Designated movement amount (L)
Al
× Am
Ap
Setting range
1 to 65535
-1
10 m
-5
10
inch
-5
10
degree
pulse
1/10/100/1000
= 0.2μm