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117
FX
3G
/FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.7 High Speed Counter [C] (FX3U/FX3UC PLC)
1
Int
roduct
ion
2
O
ver
view
3
In
str
uc
tion
Li
st
4
D
evices
in D
etail
5
Spec
ified t
he
D
evice &
C
onst
ant
6
Bef
ore
Pr
ogr
am
m
ing
7
B
asic
In
st
ru
ct
io
n
8
FN
C
00-FN
C
09
P
rogr
am
F
low
9
FN
C
10
-FN
C
19
Mo
ve
&
Co
mp
are
10
FNC2
0-F
NC2
9
Ar
ith.
&
Logic
O
per
ation
4.7.8
How to use 2-phase 2-count input counters C251 to C255 with
4 edge counting
For the 2-phase 2-count input counters C251 to C255, the edge count is usually set to 1. By using the
programs shown in the table below, the edge count may be set to 4.
Counter No.
When using 2-phase 2-count input counters with 4 edge
counting
Description
C251
1 edge count (before change)
↓
4 edge count (after change)
C252
C253
C253(OP)
C254
C255
M8000
M8198
C251
K
{{{
A phase
B phase
+1
+1
Up-counting
A phase
B phase
−
1
−
1
Down-counting
A phase
B phase
+1
Up-counting
+1 +1 +1 +1
+1 +1 +1 +1
A phase
B phase
−
1
Down-counting
−
1
−
1
−
1
−
1
−
1
−
1
−
1
−
1
M8000
M8198
C252
K
{{{
M8000
M8199
C253
K
{{{
M8388
M8199
C253
K
{{{
M8392
M8000
M8000
M8198
C254
K
{{{
M8000
M8199
C255
K
{{{