11 Use of High-speed Counters
11.5 Handling of High-speed Counters
165
FX
3G
Series Programmable Controllers
User's Manual - Hardware Edition
11
H
igh-Speed
C
ounters
12
O
utpu
t Wi
ring
13
Wi
ring for
Va
rious U
ses
14
Te
st R
un,
M
ain
tenanc
e,
Troub
le
shooting
15
Input/O
utput
Pow
ere
d
Extens
ion U
nit
s
16
Input/Output
Ex
tension
Blocks
17
Extensi
on
Pow
er Suppl
y
Un
it
18
O
ther Ex
tensi
on
Un
its
an
d
O
pti
ons
19
Displ
ay
Modul
e
20
Te
rmi
nal Block
C235 is set to the up-count or down-count mode through interruption by the count input X000.
• When the current value increases from -6 to -5, the output contact is set, and when the value decreases
from -5 to -6, it is reset.
• The current value increases and decreases regardless of the operation of the output contact. However,
when the counter’s value increments from 2,147,483,647, it changes to -2,147,483,648. In the same
manner, when it decrements from -2,147,483,648, it changes to 2,147,483,647. (This type of counter is
called a ring counter.)
• When RST instruction is executed after the reset input X011 turns on, the current counter's value resets to
0, and the output contact is restored.
• The current value, output contact operation and reset status of counters are backed up (kept) even if the
power is turned off.
11.5.2 1-phase 2-count input
These counters are 32-bit up-count/down-count binary counters.
The operations of the output contact according to the current value are the same as those of the above-
mentioned 1-phase 1-count input high-speed counters.
Examples of program
1) For C246
• While X012 is on, C246 increments the value when the input
terminal X000 switches from OFF to ON and decrements the
value when the input terminal X001 switches from OFF to ON.
• The down-count/up-count operations of C246 to C250 can be
monitored through the ON/OFF operations of M8246 to M8250.
ON: Down-counting
OFF: Up-counting
2) For C249
• While X012 is on, C249 starts counting immediately when the
input terminal X006 turns on.
The up-counting input terminal is X000, and the down-
counting input terminal is X001.
• C249 can be reset on the sequence by X011.
For C249, X002 is allocated as reset input. When X002 turns
on, C249 is immediately reset.
• The down-count/up-count operations of C246 to C250 can be
monitored through the ON/OFF operations of M8246 to
M8250.
ON: Down-counting
OFF: Up-counting
X000
Main unit
Up-counting
input
X001
Down-counting
input
The setting is (D3,D2)
X011
X012
C246
D2(D3)
RST
C246
X011
X012
C249
K1234
RST
C249
X000
Main unit
Up-counting
input
X001
Down-counting
input
X002
X006
External
reset input
External start
input
