IAI PSEL, Operation Manual

Page: 184 / 1062

174
Part 2 Programs
z
MVDI (Move relatively via direct value specification)
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 MVDI
Travel
distance
(Axis pattern) PE
[Function] Move the axis specified by the axis pattern in operand 2 from its current position by the travel
distance corresponding to the value specified in operand 1. If operand 2 is not specified, all
axes will be moved.
The output will turn OFF at the start of axis movement, and turn ON when the movement is
complete.
The travel distance is set in mm, and the set value is valid to the third decimal place.
(Note) If the specified travel distance is equal to or less than the travel distance per encoder pulse [mm/pulse], the
axis may not move.
[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
P
m/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
[Example 1] MVDI 30 11 Move all axes from the current position by 30 mm in the
positive direction.
[Example 2] LET 1 -100 Assign -100 to variable 1.
MVDI *1 1 Move axis 1 from the current position in accordance with the
content of variable 1 (-100), or by 100 mm in the negative
direction.