97
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.7 High Speed Counter [C]
1
In
troduct
io
n
2
Ov
e
rv
ie
w
3
In
st
ru
ct
ion
Li
st
4
D
evi
ce
s
in
De
ta
il
5
Speci
fied t
h
e
D
evi
ce &
C
onst
a
nt
6
Bef
o
re
Pr
ogr
a
m
m
ing
7
Bas
ic
In
st
ru
cti
o
n
8
FNC0
0
-FNC0
9
P
ro
g
ra
m F
lo
w
9
FNC1
0
-FNC1
9
M
ov
e
&
C
om
par
e
10
FNC
20-
FNC
2
9
Ar
ith.
&
Logi
c
O
per
at
io
n
4.7.8
How to use 2-phase 2-counting input counter C251 to C255 at
4 edge count.
In the 2-phase 2-counting input counters C251 to C255, the edge count is usually set to 1. By the programs
shown in the table below, the edge count is set to 4.
Counter No.
When using 2-phase 2-counting input counter at edge
count of 4
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
During forward rotation
A phase
B phase
−
1
−
1
During reverse rotation
A phase
B phase
+1
During forward rotation
+1 +1 +1 +1
+1 +1 +1 +1
A phase
B phase
−
1
During reverse rotation
−
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
{{{