
Descri
tion
Design.
Date Ed
2005.07.15
SHEET
DRAW. No.
CUST.
TITLE
Ma
Newly designed
Notice of the Update of Digital Servo
Software for Series 16i etc. (90B1/03)
B-65270EN/05-001
FANUC LTD
4/19
01
[Setting the number of position pulses]
1891 (FS15i)
Number of position pulses (PPLS)
2024 (FS30i,16i)
Set the number of position pulses according to the following equation:
(Equation for parameter calculation)
Amount of movement per motor revolution [mm]
Number of position pulses =
Detector signal pitch [mm]/512
If the calculation result is greater than 32767, use the following position
pulse conversion coefficient (PSMPYL) to obtain the parameter setting
(PPLS).
2628 (FS15i)
Position pulse conversion coefficient (PSMPYL)
2185 (FS30i,16ii)
This parameter is used when the calculation result of the number of position
pulses is greater than 32767.
(Equation for parameter calculation)
Set this parameter so that the following equation is satisfied:
Number of position pulses = PPLS × PSMPYL
(→ See FANUC AC SERVO MOTOR α
i/ βi series PARAMETER
MANUAL(B65270EN/05) Supplementary 3 in Subsection 2.1.8.)
(Example of parameter setting)
[System configuration]
• The Series 30i is used.
• A linear scale with a signal pitch of 20 µm is used.
• 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.
• 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/(0.02 mm/512)= 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
(NOTE)
There is speed limitation for the CNC except Series 30i, 31 i and 32 i. With
different signal pitch of detector, the speed limitation will change. Please
pay attention to it. (Speed < F(Px3.84) m/min)
Singal pitch Speed limitation
20µm
F76.8m/min