91
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
4.7.2
Input assignment for high speed counters
Inputs X000 to X007 are assigned as shown in the table below according to each high speed counter number.
When a high speed counter is used, the filter constant of a corresponding input number in the main unit
automatically changes (X000 to X005: 5
µ
s, X006 and X007: 50
µ
s). Input terminals not used for high speed
counters, however, can be used as general inputs.
When FX
3U
-4HSX-ADP unit is connected to an FX
3U
PLC, input terminals inside bold-line frames in the table
below are assigned to the first FX
3U
-4HSX-ADP unit, and other input terminals are assigned to the second
FX
3U
-4HSX-ADP unit.
→
For the input specifications of the FX
3U
-4HSX-ADP, refer to the FX
3U
Hardware Manual.
→
For the input specifications of the main unit, refer to the Hardware Manual of the main unit.
H/W: Hardware counter S/W: Software counter
U: Up-counting input
D: Down-counting input
A: A phase input
B: B phase input
R: External reset input S: External start input
*1.
Cautions on wiring should be considered for these high speed counters.
→
For the wiring, refer to the Hardware Manual of the main unit.
*2.
Hardware counters are switched to software counters when a comparison set/reset instruction for high
speed counter (DHSCS, DHSCR, DHSZ or DHSCT) is combined.
The counter C253 is switched to a software counter when the logic of the external reset input signal is
reversed.
→
For the condition handled as software counters, refer to Subsection 4.7.9.
*3.
When a special auxiliary relay is driven in a program, input terminal in use and those functions are
switched.
→
For the method to use a software counter as a hardware counter, refer to Subsection 4.7.7.
*4.
In a 2-phase 2-counting input counter, the edge count is usually 1. But the edge count can be set to 4
by combining a special auxiliary relay.
→
For the method to use a 2-phase 2-counting input counter with edge count of 4,
refer to Subsection 4.7.8.
Counter No.
Classifica-
tion
Input terminal assignment
X000
X001
X002
X003
X004
X005
X006
X007
1-phase
1-count-
ing input
C235
*1
H/W
*2
U/D
C236
*1
H/W
*2
U/D
C237
*1
H/W
*2
U/D
C238
*1
H/W
*2
U/D
C239
*1
H/W
*2
U/D
C240
*1
H/W
*2
U/D
C241
S/W
U/D
R
C242
S/W
U/D
R
C243
S/W
U/D
R
C244
S/W
U/D
R
S
C244(OP)
*3
H/W
*2
U/D
C245
S/W
U/D
R
S
C245(OP)
*3
H/W
*2
U/D
1-phase
2-count-
ing input
C246
*1
H/W
*2
U
D
C247
S/W
U
D
R
C248
S/W
U
D
R
C248(OP)
*1*3
H/W
*2
U
D
C249
S/W
U
D
R
S
C250
S/W
U
D
R
S
2-phase
2-count-
ing
input*
4
C251
*1
H/W
*2
A
B
C252
S/W
A
B
R
C253
*1
H/W
*2
A
B
R
C253(OP)
*3
S/W
A
B
C254
S/W
A
B
R
S
C255
S/W
A
B
R
S