Omron NX701-1 User Manual

5-17
5 Motion Control Parameters
NJ/NX-series CPU Unit Motion Control User’s Manual (W507)
5-2 Axis Parameters
5
5-2-3 Unit Conversion Settings
In this example, an OMRON 1S-series Servomotor with a 23-bit absolute encoder is used.
Mechanically, the reduction ratio of the reducer is 3/5 and the workpiece moves 10 mm for every
rotation of the ball screw.
The Unit of Display parameter is set to millimeters. The Command Pulse Count Per Motor Rotation
is set to the resolution of the encoder on the Servomotor.
The Work Travel Distance Per Rotation is set to 10 mm, which equals to the ball screw pitch.
A reducer with a reduction ratio of 3/5 is used, so the ball screw turns three times for every five rota-
tions of the Servomotor. For this reduction ratio setting, the work gear ratio is set to 3 and the motor
gear ratio is set to 5.
With these settings, the command unit for positions in the user program is 1 mm.
For example, to move to an absolute position of 100.5 mm, the Position (Target Position) input vari-
able to the MC_MoveAbsolute (Absolute Positioning) instruction is set to 100.5.
 When Using a Reducer and the Count Mode Is Rotary Mode
When you set to use a reducer and the Count Mode is Rotary Mode, the following calculation for-
mula is used to have the electric gear ratio.
In Rotary Mode, the Work Travel Distance Per Rotation is automatically determined and set by the
result of “Modulo maximum position - Modulo minimum position”.
Precautions for Correct UsePrecautions for Correct Use
The electronic gear converts units to the values that are used for positioning by the MC Func-
tion Module and motion control instructions.
Motion control instructions specify the target position as LREAL data. However, an instruction
error will occur if the command position after conversion to pulses by the electronic gear
exceeds 40 bits.
Parameter name Setting
Unit of Display mm
Command Pulse Count Per Motor Rotation 8,388,608
Work Travel Distance Per Rotation 10
Work Gear Ratio 3
Motor Gear Ratio 5
Reduction ratio: 3/5 Ball screw pitch: 10 mm
Servomotor encoder
resolution: 23 bits/rotation
(8,388,608 pulses per rotation)
Workpiece
Electronic gear ratio =
Command Pulse Count Per Motor Rotation
× Motor Gear Ratio
Command Pulse Count Per Motor Rotation
× Motor Gear Ratio
Work Travel Distance Per Rotation
× Work Gear Ratio
=
(Modulo maximum position - Modulo minimum position)
× Work Gear Ratio

Omron NX701-1 Specifications

General

Brand	Omron
Model	NX701-1
Category	Controller
Language	English