Yaskawa MP920 Motion Module - Manual (Page 58)

2 Motion Control
2.3.1 Prerequisites for Position Control
2-32
Electronic Gear Parameter Setting Example (B): Rotating Load
In the above machine system, if the requirement is reference unit = output unit = 0.1 °, the
setting of each parameter will be as follows:
•
•
• No.21 = 3
• No.22 = 1
„ Axis Selection
There are two types of position control: Finite length position control, where return and
other operations are performed only within a specified range, i.e., within a prescribed posi-
tioning interval, and infinite length position control, which is used for rotation in one direc-
tion only.
There are two infinite length position control methods. One method involves resetting the
conveyor belt or other device to “0” after one rotation; the other method involves rotating
the conveyor belt in one direction only, without resetting after one rotation.
Axis selection involves selecting which of these types of position control is to be used. The
axis selection is set in bit 5 of motion fixed parameter No. 17 (Motion Controller Function
Selection Flags).
When motion commands (OW††20) are not used, axis selection is disabled. (Set as a finite
length axis (= 0).)
* The reset position is set in motion fixed parameter No. 23 (Infinite
Length Axis Reset Position).
Table 2.13 Axis Selections
Types of Position Control Axis Selection
Finite length position control Finite length axis
(= 0)
Infinite length position control that rotates the axis in
one direction only, without resetting after one rotation Finite length axis
(= 0)
Infinite length position control that resets the axis after
one rotation* Infinite length axis
(= 1)
Motor
m
n
30 rotations
Rotating load
360 °/rotation
10 rotations
No.19 = =
3600
360 °
0.1 °
Gear ratio = = =
n
m
10
30 1
3