
16. DIGITAL SERVO
841
Example)
(1µ m)
300mm ⇒ reference counter 30000
20000
15000
10000 etc
16.6.1.3 Reference position shift
When reference position return is performed using the grid method, the
reference position can be shifted by a parameter–set distance without
having to move the deceleration dog.
D How to adjust the reference position
(1) Set the PRM1002#2(SFD) to 1, and set the PRM1850 for reference
position shift amount to 0. Then, perform reference position return.
After the deceleration dog is turned off, the tool stops when the first grid
point is reached. Distance L
DEC
is indicated on the DGN302.
L
DEC
L
SFT
Direction of reference position return
Deceleration dog
↑
Reference position
Grid point
↑↑
Stop position
L
SFT
: Reference position shift amount
L
DEC
: Distance from the position where the deceleration dog is turned
off to the first grid point (grid point when the shift amount is 0)
(2) Determine the distance L
SFT
(reference position shift amount) from the
stop position to the reference position, and set it in PRM1850.
This completes the adjustment of the reference position.
(3) Perform reference position return again. The tool stops when it reaches
the reference position.
Direction of reference position
return
Deceleration dog
↑
Reference position
(stop position)
Grid point
↑
NOTE1 The reference position can be shifted only in the direction of refer-
ence position return.
NOTE2 When the PRM1002#2(SPD) is 0, only the distance from the posi-
tion where the deceleration dog is turned off to the first grid point
(the grid point after grid shift) is indicated.