Mitsubishi Electronics FX3G User Manual

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3S

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3G

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3GC

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3U

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3UC

 Series

Programming Manual - Basic & Applied Instruction Edition

13 High-Speed Processing – FNC 50 to FNC 59

The input pulse 

 is counted only for 

 

× 1 ms. The measured value is stored in 

, the present value is

stored in 

+1, and the remaining time is stored in 

+2 (ms).

By repeating this operation, the measured value 

 will store the pulse density (which is proportional to the

rotation speed).

1) Timing chart

2) The measured value 

 is in proportion to the number of rotations as shown below:

  

S

1

  

S

2

   

D

   

D

   

D

   

D

FNC 56

SPD

S

1

 

D 

S

2

 

Command

input

Measured

value

The command contact is set to ON.

Command

input

S

1

 

D 

         + 1 counts "OFF 

→ ON" operation of           .

         ms later, the counting result is stored to           .
Accompanied by this operation,           +1 is reset, and
then counting of the "OFF 

→ ON" operation of            is

started again.

S

1

 

D 

S

2

 

D 

D 

S

1

 

         + 2 is used to measure the remaining time.

D 

Remaining time (ms)

D 

+2

Counting time

ms

S

2

 

Counting time

ms

S

2

 

Current value

D 

+1

ms

S

2

 

   

D

N (rpm)

Input X000

Proximity switch
"n" pulses/rotation

N = 60        

nt

 ´ 10  (r/min)

3

t: Measurement time duration specified as          (ms)

S

2

  D