
B-65270EN/05 2. SETTING αiS/αiF/βiS SERIES SERVO PARAMETERS
- 29 -
[Number of position pulses]
Parameter No. 1891 (Series 15i) or No. 2024 (Series 30i, 16i, and so
on)
Number of position pulses
= Amount of movement per motor revolution [mm] /
minimum resolution of the detector [mm]
* If the result of the above calculation does not fall in the setting
range (0 to 32767) for the number of position pulses, use
“position feedback pulse conversion coefficient” to specify the
number of position pulses according to the following procedure.
Number of position pulses to be set = A × B
Select B so that A is within 32767. Then, set the following:
A: Position pulses parameter (32767 or less)
No.1891 (Series15
i), No.2024 (Series 30i, 16i, and so on)
B: Position pulses conversion coefficient parameter
No.2628 (Series15
i), No.2185 (Series 30i, 16i, and so on)
(Example of parameter setting)
[System configuration]
• The Series 16i is used.
• A linear encoder with a signal pitch of 20 µm is used.
• The linear encoder is coupled with high-resolution serial output
circuit H.
• The least input increment of the controller is 1 µm.
• The amount of movement per motor revolution is 16 mm.
[Parameter setting]
• To enable a separate detector, set bit 1 of parameter No. 1815 to
1.
• To use high-resolution serial output circuit H, set bit 0 of
parameter No. 2274 to 1.
Minimum resolution of the detector = 20 µm/512
= 0.0390625 µm
• Calculate the parameters for the flexible feed gear.
Because flexible feed gear (N/M)=(20/512µm)/1µm=5/128
No.2084=5, No.2085=128
• Calculate the number of position pulses.
Number of position pulses = 16 mm/(20/512µm) = 409,600
Because this result does not fall in the setting range (0 to 32767),
set A and B, respectively, with the "number of position pulses"
and "position pulses conversion coefficient" by assuming:
409,600 = 25,600 × 16 → A = 25,600, B = 16
No.2024 = 25,600, No.2185 = 16