Mitsubishi Electric FX3G SERIES Programming Manual page 374

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Explanation of function and operation
1. 16-bit operation (SPD)
The input pulse
stored in D
By repeating this operation, the measured value
rotation speed).
Command
input
FNC 56
1) Timing chart
Command
input
S
1
D
Current value
S
2
2) The measured value
N(rpm)
372
S is counted only for
1
+1, and the remaining time is stored in
S S
1 2
SPD
+1
D
Measured
value
S S
2 ms 2
Counting time Counting time
ms
D +2
Remaining time (ms)
D is in proportion to the number of rotations as shown below:
Input X000
Proximity switch
"n" pulses/rotation
13 High-Speed Processing – FNC 50 to FNC 59
× 1 ms. The measured value is stored in
S
2
D +2 (ms).
D will store the pulse density (which is proportional to the
D
The command contact is set to ON.
+ 1 counts "OFF → ON" operation of
D
ms later, the counting result is stored to
S
2
Accompanied by this operation,
then counting of the "OFF → ON" operation of
started again.
ms
D + 2 is used to measure the remaining time.
D
60
× 10 (r/min)
N =
nt
t: Measurement time duration specified as
13.7 FNC 56 – SPD / Speed Detection
D , the present value is
D +1 is reset, and
3
S .
1
.
D
is
S
1
S (ms)
2