IAI America ASEL User Manual

Page 168

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Part 2 Programs

Chapter 3 Explanation of Commands

146

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 [256 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

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