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7
Data Flow
PC
BUS
I/F
C200H PC
Position Control Unit C200H-NC112
Rotary encoder
Tachogenerator
Servomotor driver
Pulse train
Power
amplifier
Pulse
train
Stepping motor driver
I/O
interface
MPU
Memory
Pulse
generator
Magnetizing
distributor
circuit
Servomotor
(Positioning output)
PC
bus
I/F
External
input
Stepping motor
Error counter
Power amplifier
I/O Connector
1–5–1
Open-loop System
In an open-loop system, the Position Control Unit outputs pulse trains as
specified by the PC program to control the angle of rotation of the motor. Be-
cause the Unit outputs pulse trains, it is generally used with a stepping motor.
The angle of rotation of a stepping motor can be controlled through the num-
ber of pulse signals supplied to the motor driver. The number of rotations of
the stepping motor is proportional to the number of pulses supplied by the
Unit, and the rotational speed of the stepping motor is proportional to the fre-
quency of the pulse train.
Positioning System Principles