IAI America SSEL - Manual (Page 180)

158
Part 2 Programs
z OVRD (Override)
Command, declaration
Extension condition
(LD, A, O, AB, OB)
Input condition
(I/O, flag)
Command,
declaration
Operand 1 Operand 2
Output
(Output, flag)
Optional Optional OVRD Speed ratio Prohibited CP
[Function] Reduce the speed in accordance with the ratio specified in operand 1 (speed coefficient
setting). The speed ratio is set in a range from 1 to 100%.
A speed command specifying a speed below 1 mm/sec can be generated using OVRD.
[Example 1] VEL 100 Set the speed to 100 mm/s.
OVRD 50 Reduce the speed to 50%.
As a result, the actual speed will become 50 mm/s.
Command limit speed for smooth operation: Travel distance per encoder pulse
[mm/pulse]/time [msec]
Command limit speed that can be generated: Travel distance per encoder pulse
[mm/pulse]/time [msec]
(Smoothness of actual operation cannot be guaranteed. Movement must be checked on the
actual machine.)
[Calculation formula of travel distance per encoder pulse]
Rotary encoder
Travel distance per encoder pulse [mm/pulse] = (Screw lead [0.001 mm] x Gear ratio
numerator)
/ (Encoder resolution [pulses/rev] x Gear
ratio denominator
/ (2 ^ Encoder division ratio)
Linear encoder
Travel distance per encoder pulse [mm/pulse] = Encoder resolution (0.001
Pm/pulse) x 1000
/ (2 ^ Encoder division ratio)
(Reference) Use the values of the following parameters for the above calculation formulas:
Encoder resolution: Axis-specific parameter No. 42
Encoder division ratio: Axis-specific parameter No. 43
Screw lead: Axis-specific parameter No. 47
Gear ratio numerator: Axis-specific parameter No. 50
Gear ratio denominator: Axis-specific parameter No. 51