Chapter 7 Usage of Various Functions

(6)RPM setting

-Can calculates RPM of input pulse

-RPM is stored in designated device.

- The RPM is expressed as:

RPM = (CurrentValue- Last Value)⋅ 60,000

Pulsesper rotate⋅ refreshcycle[ms]

(a)Examples of Program

-Refresh cycle : 1000ms, Pulses per rotate : 60, RPM save area : D0

Input pulse

 

 

 

 

Current value

1000

2000

2001

4000

 

D0, D1

500

 

1000

2000

Time

 

1000ms

 

2000ms

3000ms

 

 

Last value = 500(Assumption), Current value = 1000 RPM = { (1000 – 500) * 60,000} / {60 * 1000} = 500

Last value = 1000, Current value = 2000

RPM = { (2000 – 1000) * 60,000} / {60 * 1000} = 1000

Last value = 2000, Current value = 4000

RPM = { (4000 – 2000) * 60,000} / {60 * 1000} = 2000

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LG Electronics 120S user manual Usage of Various Functions