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5.3 Position control 
5.3.1 General position control 
5.3.1.1 Electronic gear ratio 
1. Overview 
The so-called "electronic gear" function has two main applications: 
(1) Determine the number of command pulses needed to rotate the motor for one revolution to 
ensure that the motor speed can reach the required speed. 
As an example of 17-bit encoder motor, the pulse frequency sent by the upper computer PLC is 
200kHz: 
Pulses per revolution set to 10000 
Electronic gear ratio set to 131072:10000 
Set pulses per revolution to 5000 
Electronic gear ratio set to 131072:5000 
Max speed 
600rpm
Two circle radius ratio: 2:1
Big circle run one rotation (need 20000 
pulses), small circle run two rotations. 
Max speed 
1200rpm
Two circle radius ratio: 2:1
Big circle run one rotation (need 10000 
pulses), small circle run two rotations. 
(2) In the precise positioning, the physical unit length corresponding to 1 command pulse is set for 
calculation. 
For example: the object moves 1um per command pulse. The command pulses of load rotating one 
circle = 6mm / 1um = 6000. In the case of deceleration ratio is 1:1, set pulse per rotation P0-11=6000, 
P0-12=0. Then if the PLC outputs 6000 pulses, the object will move 6mm. 
                    
Encoder: 131072(17-bit) ball screw pitch: 6mm 
 
Do not change the electronic gear ratio 
Change the electronic gear ratio 
Without changing the ratio of the electronic 
gear  to  the  motor,  the  rotating  cycle  is 
131072 pulses (P 0-11=0, P 0-12=0). 
If the workpiece is moved 6 mm in one turn, 
the number of pulses needed is 131072. If the 
workpiece  is  moved  10  mm,  it  will  need 
10/6*131072=218453.333  pulses.  When  the 
decimal  number  is  omitted,  the  error  will 
occur. 
By  changing  the  electronic  gear  ratio,  the 
motor needs 6000 pulses to rotate one circle. 
If the workpiece moves 6 mm in one turn, the 
number  of  pulses  needed  is  6  000.  If  the 
workpiece  is  moved  10  mm,  it  needs 
10/6*6000 = 10000 pulses. When the pulse is 
sent, the decimal number will not be produced 
and the error will not be produced. 
  Related parameters 
Pulse numbers per rotation *1 
Pulse numbers per rotation *10000 
Electronic gear ratio (numerator) 
Electronic gear ratio (denominator) 
Group 2 Electronic gear ratio 
(numerator) low bit*1