Position References - YASKAWA SVC User Manual

5.1 Motion Parameters

5.1.4 Position References

5.1.4

Position References

The target position for position control is set in the OL
erence Setting). There are two different methods of setting the position reference: the absolute
value specification method, which sets the coordinate data for the target position directly, and
the incremental addition method, which adds the current travel amount to the previous position
reference value.
The parameters that are related to setting the position reference are listed in the following table.
Parameter
Type
Setting
Parameters
The following table compares the merits and demerits of the incremental value addition and
absolute value specification methods.
Position
Reference Type
Incremental value
addition method
Absolute value
specification
method
Setting the Target Position for an Infinite-length Axis
There are two methods that you can use to set the target position when an infinite-length axis
is used.
In the following cases, use setting method 1 to set the target position.
• When executing a POSING command when no command (NOP) is being executed
5-6
Register
Name
Address

OW 09 Position Ref-
Bit 5 erence Type
Position Ref-

OL 1C erence Set-
ting
Merit
It is not necessary to consider the relation-

ship between OL
position when a move is canceled.
The coordinate of the target position is
specified directly, making it easy to under-
stand.

1C setting parameter (Position Ref-
Description
This parameter specifies the type of position reference
data.
0: Incremental value addition method

This method sets OL

OL 1C plus the current travel distance.
1: Absolute value specification method

This method sets OL
value of the target position.
Setting Precautions
Always set this parameter to 0 when a motion pro-
gram is used.
This parameter sets the position data.
• If the incremental value addition method is used (i.e.,

if bit 5 in OW 09 is set to 0), the current travel
distance (incremental amount) is added to the cur-

rent value of OL
 
OL 1C = OL
tance
Example:
If the current travel distance is 500 and the previous

value of OL 1C is 1,000, OL
1,000 + 500 or 1,500.
• If the absolute value specification method is used

(i.e., if bit 5 in OW
ter is set to the coordinate value of the target posi-
tion.
Example:

Set OL 1C to 10,000 to move to the position
10,000.

OL 1C = 10000

OL
1C and the current tion, so the position reference can be difficult
to understand intuitively.
The current position must be set in

OL
turned ON or a move is canceled. If this
operation is not performed, the axis may
move suddenly when a movement motion
command is started.
This method also makes the target position
difficult to manage for infinite-length axes.
1C to the current value of
1C to the coordinate
1C.
1C + Incremental travel dis-

1C will equal
09 is set to 1), this parame-
Demerit
1C does not equal the target posi-
1C whenever the power supply is
Default
0
0