Filter
Top Products
372
FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
13 High-Speed Processing – FNC 50 to FNC 59
13.7 FNC 56 – SPD / Speed Detection
Explanation of function and operation
1. 16-bit operation (SPD)
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)
S2
D