Yaskawa MP940 - Manual (Page 436)

Motion Control
11.3.1 Prerequisites for Position Control
11-34
„ Position Reference
There are two methods of setting the position reference: Direct designation, which directly
sets the position reference in OLC012, and indirect designation, which specifies the number
of the position buffer from which the position reference is stored in OLC012.
There are two direct designation methods: The absolute position reference mode, in which
the absolute position is set in OLC012, and the incremental addition mode, in which the
present travel distance is added to the previous position reference value (previous value of
OLC012).
The following table shows the parameters relating to the position reference.
Table 11.10 Position Reference Parameters
∗ 1. This parameter is invalid when the position reference value selection
is the position buffer (indirect designation).
∗ 2. The setting data differs according to the setting of the Position Refer-
ence Value Selection (bit 12 of OWC001) and the Position Reference
Type (bit 14 of OWC001).
• When indirect designation is used to specify the position buffer number, the positions stored in the
position buffer are treated as absolute positions.
When a motion command (OWC020) is not used, the position reference value set in OLC012 is
treated as an absolute position.
• Be sure to set the motion set parameter OWC001 bit 14 (Position Reference Type) to l ( = incremen-
tal addition mode) when using the motion program.
Parameter Type
Parameter No.
(Register No.)
Name Description
Initial
Value
Motion Setting
Parameters Bit 12 of
OWC001 Position
Reference Value
Selection Sets the position reference designation method.
• 0: Direct designation
Directly sets the position data in OLC012.
Specifies in bit 14 of OWC001 whether the
position data is to be set in the absolute posi-
tion mode or the incremental addition mode.
• 1: Indirect designation
Sets the number of the position buffer in
OLC012. The absolute position must first be
stored in the specified position buffer.
0
Bit 14 of
OWC001 Position
Reference Type Specifies the type of position data.
• 0: Absolute position mode
Sets the absolute position in OLC012.
• 1: Incremental addition mode
Adds the present travel distance value to the
previous value of OLC012 and sets the result
in OLC012.*1
1
OLC012 Position
Reference
Setting Sets the position data.*2 0